Double Strength Joint Soother Glucosamine Chondroitin MSM by Puritan's Pride

POSSIBLY EFFECTIVE

• Osteoarthritis. Oral Boswellia serrata extracts, taken alone or in combination with other ingredients, appear to reduce pain and improve function in knee osteoarthritis. However, most clinical studies have been small and methodologically flawed. Details: A meta-analysis of small, randomized, controlled trials in patients with knee osteoarthritis shows that taking Boswellia serrata extract 100-250 mg daily for 1-3 months moderately reduces pain and improves function when compared with placebo (103785). However, the validity of the included studies is limited by incomplete reporting, inadequate blinding, and other methodological issues. Studies included in the meta-analysis tested a specific Boswellia serrata extract (5-Loxin), as well as a specific Boswellia serrata gum resin extract (ApresFLEX, also known as Aflapin). Pain reduction was first noted within 7 days of treatment (17948,17949,21145). More recent evidence on the use of a Boswellia serrata gum resin extract (Aflapin) 100 mg daily for 30 days is consistent with the findings in this meta-analysis (109564). Lower quality studies, not included in the meta-analysis, tested another specific Boswellia serrata gum resin extract (Wokvel, Pharmanza). When taken in a dose of 333 mg three times daily for 2-6 months, this product improves pain and knee function when compared with control. Wokvel seems to have comparable benefit to a solid lipid Boswellia serrata particle product (Wokvida) (12432,21146,103784). Finally, another clinical trial not included in the meta-analysis shows that taking a different Boswellia serrata extract (Boswellin, Sabinsa Corp.) 169 mg twice daily for 4 months also moderately improves pain, stiffness, functional ability, and quality of life when compared with placebo (100699). Several studies also show that taking specific combination products containing Boswellia serrata and other ingredients can improve pain and functionality in patients with osteoarthritis. These products have combined Boswellia serrata 100 mg with ashwagandha 450 mg, turmeric 50 mg, and zinc complex 50 mg (Articulin-F) three times daily for 3 months (19276); Boswellia serrata 100 mg with ginger 33.33 mg, Tinospora cordifolia 73.33 mg, and Indian gooseberry 166.66 mg three times daily for 6 months (89557); a specific Boswellia serrata extract (BosPure, Arjuna Natural Extracts Ltd) 300 mg with turmeric extract (BCM 95, Arjuna Natural Extracts Ltd) 700 mg daily for 12 weeks (89719); boswellic acid 7.2 mg (from Boswellia serrata) with methylsulfonylmethane 5 grams and vitamin C daily for 2 months (96446); and a specific combination product (Tregocel, Max Biocare) providing Boswellia serrata extract 1 gram, curcumin 100 mg, devil's claw tuber 1 gram, celery seed 1 gram, and ginger rhizome 330 mg daily for 36 weeks (106078). However, research in patients with osteoarthritis of the hand suggests that taking a combination of Boswellia serrata extract 250 mg, pine bark extract 100 mg, methylsulfonylmethane 1500 mg, and curcumin 168 mg daily for 12 weeks does not improve pain or functionality (109563).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). Although there is interest in using oral Boswellia serrata for hay fever, there is insufficient reliable information about the clinical effects of Boswellia serrata for this condition.
• Alzheimer disease. It is unclear if oral Boswellia serrata improves cognitive function in patients with Alzheimer disease. Details: A small clinical study in adults with mild to moderate Alzheimer disease shows that taking a specific Boswellia serrata extract (K-Vie, Kondor Pharma) 1200 mg daily for 6 months improves neuropsychiatric symptoms, dementia severity, and some but not all measures of cognitive function when compared with placebo (112807).
• Aromatase inhibitor-induced arthralgia. Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with estrogen receptor positive (ER+) breast cancer and aromatase inhibitor-induced arthralgia shows that taking a specific combination product (Opera, Gamfarma Srl) containing Boswellia serrata 40 mg, alpha-lipoic acid 240 mg, methylsulfonylmethane 200 mg, and bromelain 20 mg once daily for 6 months reduces arthralgia intensity when compared to baseline, with around 22% of patients having complete symptom resolution at the end of the study (109570). The validity of these findings is limited by a lack of control group.
• Asthma. It is unclear if oral Boswellia serrata can improve symptoms of asthma. Details: One small preliminary clinical study in patients with asthma suggests that taking a specific Boswellia serrata gum resin (S-compound, Rahul Pharma) 300 mg three times daily for 6 weeks may improve symptoms of asthma, such as forced expiratory volume (FEV), the number of asthma attacks, and dyspnea and rhonchi, in 70% of patients, compared to only 27% of patients in a control group (1708).
• Brain tumor. It is unclear if oral Boswellia serrata improves outcomes in patients with brain tumors. Details: One small clinical study in adults with brain tumors undergoing radiation therapy shows that taking an H15 Boswellia serrata extract 4200 mg in three divided doses daily throughout radiotherapy reduces cerebral edema and tumor volume, but not dexamethasone dosage, when compared with placebo (21149).
• Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS). Rectal Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Two small, open-label clinical studies in males with prostatitis-like symptoms or CP/CPPS types IIIa or IIIb shows that rectal administration of a specific suppository containing Boswellia serrata resin extract and propolis polyphenols (MICTALASE) once daily for 20 days or once daily for 15 days per month for 3 months improves pain, urinary symptoms, quality of life, and total symptom scores, as measured by the Chronic Prostatitis Symptom Index (CPSI), when compared to baseline. However, there were no improvements in scores on the International Index of Erectile Dysfunction (IIED), and studies showed mixed findings regarding improvements on the International Prostate Symptoms Score (IPSS) (102091,109566). The validity of these results is limited by the lack of a comparator group.
• Cluster headache. Although there is interest in using oral Boswellia serrata for cluster headache, there is insufficient reliable information about the clinical effects of Boswellia serrata for this condition.
• Coronavirus disease 2019 (COVID-19). Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults hospitalized with moderate COVID-19 infection in Egypt shows that taking Boswellia serrata extract 300 mg and licorice extract 300 mg twice daily for 14 days, along with conventional therapy, reduces the risk of death, shortens the time to hospital discharge by around 5.5 days, and reduces the rate of mechanical ventilation when compared with placebo. For every five patients treated with this combination product, one additional patient survived. The standard treatments administered in this study included azithromycin, vitamin C, and zinc (108579). Another large clinical study in adults hospitalized with moderate COVID-19 infection in India shows that taking a specific product containing Boswellia serrata, ashwagandha, ginger, and turmeric (Artovid-20, Bioved Pharmaceuticals, Inc) 1,776 mg twice daily after meals for 14 days, starting within 48-96 hours of symptom onset along with conventional therapy, decreases the duration of illness by about 1 day and reduces patient-assessed severity scores of various symptoms (e.g. nasal congestion, sore throat, cough, taste and smell disorders) when compared with placebo. Almost all patients in this study also received steroids, and over 50% received remdesivir. Study results were similar in the subgroup of patients who received remdesivir (109899). However, the validity of this study is limited by use of data only from patients who fully adhered to the study protocol per protocol analysis and exclusion of patients with risks for progression to severe COVID-19, including uncontrolled hypertension, asthma, chronic obstructive pulmonary disease, diabetes, obesity, or immunocompromise.
• Crohn disease. It is unclear if oral Boswellia serrata reduces relapse rates in patients with Crohn disease. Details: One small clinical study in patients with Crohn disease who are in remission shows that taking Boswellia serrata (Boswelan, Pharmasan) 800 mg orally three times daily for one year does not decrease relapse rates or improve quality of life when compared with placebo (17241).
• Diabetes. It is unclear if oral Boswellia serrata improves glycemic control in patients with diabetes. Details: A small clinical study in patients with diabetes who are taking metformin shows that taking powdered Boswellia serrata gum resin 400 mg twice daily after meals for 12 weeks modestly decreases fasting blood glucose, glycated hemoglobin (HbA1c), insulin, and lipid levels when compared with a toasted powder placebo (91378). In contrast, another small clinical study in patients with diabetes shows that taking capsules containing powdered Boswellia serrata gum 250 mg (standardized for 60% boswellic acids) twice daily after meals for 8 weeks does not improve fasting blood glucose, HbA1c, other glycemic parameters, or lipid levels when compared with placebo (105010). However, the interpretation of these findings, specifically the lack of improvement in HbA1c, may be limited by the short duration of the study. A meta-analysis pooling the results of the two trials described above shows that Boswellia serrata reduces HbA1c by about 0.5% and fasting blood glucose by about 24 mg/dL, with no improvement in lipid levels, when compared with placebo (111503).
• Diarrhea. It is unclear if oral Boswellia serrata is beneficial in patients with acute diarrhea. Details: A small clinical study in adults with acute diarrhea shows that taking a specific lecithin-based delivery form of Boswellia serrata extract (Casperome, Indena S.p.A.) 250 mg twice daily for 5 days decreases the time to diarrhea resolution by nearly 1.4 days, reduces stool frequency, and improves symptoms of abdominal pain and nausea when compared with placebo (109568).
• Dysmenorrhea. Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with moderately painful dysmenorrhea shows that taking a single dose of a combination product containing Boswellia serrata, turmeric, and sesame (Rhuleave-K, Arjuna Natural Private Ltd.) 1000 mg at the start of menstruation relieves menstrual cramp pain and reduces pain intensity for up to 6 hours when compared with placebo (112806). It is unclear if these effects are due to Boswellia serrata, other ingredients, or the combination.
• Exercise-induced muscle soreness. Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in healthy active adults with moderate to severe exercise-induced muscle pain shows that taking a single, 1000-mg dose of Boswellia serrata and turmeric extracts in black sesame oil (Rhuleave-K; Arjuna Natural Private Ltd.) improves pain relief when compared with placebo, with maximal benefits within about 3 hours. The number of people needed to treat to obtain pain relief of at least 50% over a 6-hour period was 1.1 (109277).
• Irritable bowel syndrome (IBS). Small clinical studies suggest that an oral Boswellia serrata extract may improve symptoms of IBS. Details: A small clinical study in patients with mild IBS shows that taking a specific lecithin-based delivery form of Boswellia serrata extract (Casperome, Indena S.p.A.) 250 mg daily for 6 months reduces abdominal pain, cramps, and gas when compared with standard management with hyoscine butylbromide or papaverine hydrochloride plus belladonna extract 10 mg. Patients receiving Casperome required fewer rescue medications and had a 46% lower risk of needing additional medical care, including hospitalization (100713). In a short-term clinical trial of the same Boswellia serrata extract 250 mg daily for 4 weeks, the risk for requiring additional medical care was reduced by 67% when compared with the same standard treatment options above. While IBS symptoms improved over baseline, significant differences between Casperome and standard treatment options were lacking (102089). These studies were funded by the supplement manufacturer, which may limit the reliability of these findings.
• Knee pain. It is unclear if oral Boswellia serrata is beneficial for knee pain. Details: A small clinical study in otherwise healthy adults with knee pain shows that taking Boswellia serrata extract 12.5% tablets twice daily for 8 weeks improves physical function and pain but not stiffness, functional mobility, muscle function, or level of physical activity when compared to baseline (112808).
• Menorrhagia. It is unclear if oral Boswellia serrata is beneficial for menorrhagia. Details: A small clinical study in otherwise healthy adults with menorrhagia shows that taking Boswellia serrata oleoresin powder 300 mg three times daily for 7 days, repeated over 2 menstrual cycles, improves quality of life and modestly reduces the average duration of menstrual bleeding after the second cycle when compared with placebo. All patients were permitted to use ibuprofen 200 mg as needed (105401).
• Microscopic colitis. There is limited evidence on the oral use of Boswellia serrata in patients with collagenous colitis. Details: One small clinical trial shows that taking Boswellia serrata extract 400 mg three times daily for 6 weeks increases the clinical remission rate by 64% when compared with placebo in patients diagnosed with a type of microscopic colitis called collagenous colitis. Clinical remission was defined as having an average of three or fewer soft or solid stools daily during the last week of the study (21152).
• Pain (acute). Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with acute musculoskeletal pain shows that taking a specific combination product containing Boswellia serrata and turmeric extracts in black sesame oil (Rhuleave-K; Arjuna Natural Private Ltd.) 1000 mg daily for 7 days is as effective as acetaminophen 1000 mg daily for pain relief, onset of pain relief, and onset of maximal pain relief (109287). This study is limited by its lack of blinding and placebo control. Additionally, the dose of acetaminophen used in this study is below the standard recommended daily dose.
• Rheumatoid arthritis (RA). Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical trial in patients with RA shows that taking two capsules of a specific product containing Boswellia serrata 100 mg, ashwagandha 450 mg, turmeric 50 mg, and zinc complex 50 mg (Articulin-F) three times daily for 3 months improves pain, morning stiffness, grip strength, and disability scores when compared with placebo (21154). However, another clinical trial in patients with RA shows that taking two tablets of a standardized extract formulation (RA-1) containing Boswellia serrata, ashwagandha, ginger, and turmeric three times daily for 16 weeks does not improve most symptoms when compared with placebo (21155).It is unclear if these findings are due to Boswellia serrata, other ingredients, or the combination.
• Rhinosinusitis. Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients over 12 years of age with chronic sinusitis shows that taking a combination product containing Boswellia serrata, black currant, bromelain, and vitamin D (Flogostop Forte, Humana Italia) with inhaled corticosteroids daily for 30 days reduces rhinorrhea, hyperemia of mucosa, and local inflammation when compared with inhaled corticosteroids alone (111501). It is unclear if these findings are due to Boswellia serrata, other ingredients, or the combination. Pharyngitis. Although there is interest in using oral Boswellia serrata for pharyngitis, there is insufficient reliable information about the clinical effects of Boswellia serrata for this condition.
• Stroke. It is unclear if oral boswellic acids improve neurological function after stroke. Details: One small clinical study in adults with recent ischemic stroke who are taking aspirin and clopidogrel shows that taking boswellic acids 800 mg three times daily for 30 days improves neurological function, as measured using the National Institutes of Health Stroke Scale, when compared with placebo (102092).
• Traumatic brain injury (TBI). It is unclear if oral Boswellia serrata is effective for reducing disability, or improving cognitive function or memory in adults recovering from TBIs. Details: A small clinical crossover study in adults admitted to the hospital for diffuse axonal injury shows that taking powdered Boswellia serrata oleogum resin 360 mg three times daily for 6 weeks does not improve disability when compared with placebo (91379). However, another small clinical study in patients suffering from a TBI 3 months to 3 years earlier shows that taking a specific Boswellia serrata extract (K-Vie, Kondor Pharma) 400 mg three times daily for 3 months improves performance on cognitive function tests, including those assessing processing speed, memory, and overall cognitive function, when compared with placebo (109567). A moderate-size clinical study in adults with memory dysfunction due to a recent mild traumatic brain injury in Iran shows that taking a specific product containing Boswellia serrata 360 mg and ginger 36 mg (Memoral, Goldarou) three times daily for 1 month modestly improves practitioner-assessed memory function scores when compared with placebo (110132). However, it is unclear if this effect is due to Boswellia serrata, ginger, or the combination.
• Ulcerative colitis. Small clinical studies suggest that oral Boswellia serrata extracts may improve symptoms of ulcerative colitis. Details: Two very small clinical trials in patients with active ulcerative colitis suggest that taking Boswellia serrata gum resin 300-350 mg three times daily for 6 weeks improves symptoms and disease markers comparably to taking sulfasalazine 1 gram three times daily (1709,12438). These findings are limited because the sample size may have been inadequate to assess differences between groups. In patients with ulcerative colitis in remission, one observational study has found that taking a specific lecithin-based delivery form of Boswellia serrata extract (Casperome, Indena S.p.A.) 250 mg daily for 4 weeks is associated with a reduction in abdominal pain, cramps, and malaise, a decrease in the need for additional medications, and a 58% lower risk for requiring additional medical care when compared with no treatment. Additionally, weekly episodes of bloody diarrhea, bowel movements, and watery stools were reduced when compared with baseline (102090).
• Urinary incontinence. Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in postmenopausal adults with urinary incontinence shows that taking a 3 tablets of a multi-ingredient herbal product containing Boswellia serrata 100 mg and five other herbs twice daily for 4 weeks reduces urinary incontinence frequency and leakage amount when compared with placebo, with improvements similar to those reported with solifenacin as standard therapy (111502). It is unclear if these effects are due to Boswellia serrata, other ingredients, or the combination.
• Urinary tract infections (UTIs). Oral Boswellia serrata has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small observational study in patients with an uncomplicated UTI has found that taking two tablets of a specific combination product (Acidif plus) containing Boswellia serrata gummy dry extract 100 mg, L-methionine 400 mg, and hibiscus 100 mg daily for 7 days is associated with reduced UTI symptoms and reduced bacteriuria when compared with taking an unreported dose of fosfomycin for 2 days (103783). The validity of this study is limited by its observational nature and a lack of information on the severity of UTI at baseline. Also, it is unclear if these effects are due to Boswellia serrata, other ingredients, or the combination. More evidence is needed to rate Boswellia serrata for these uses.

(Read more about BOSWELLIA SERRATA)

POSSIBLY EFFECTIVE

• Cataracts. Chondroitin sulfate in combination with sodium hyaluronate is approved as a medical device to be ophthalmically injected during cataract surgery. It is unknown if other routes of administration are beneficial. Details: Injecting ophthalmic viscosurgical devices (OVDs) containing a combination of chondroitin sulfate and sodium hyaluronate into the eye protects the corneal endothelium during small-incision cataract surgery. Various medical devices containing chondroitin sulfate and sodium hyaluronate (Viscoat, Alcon Laboratories) have been granted approval by US Food and Drug Administration (FDA) for use as an adjunct to cataract surgery (89436,89437). However, OVDs that cannot be easily removed after surgery can cause intraocular pressure (IOP) spikes and reduced visual acuity. A meta-analysis of small clinical studies shows that using a specific chondroitin sulfate 4% and sodium hyaluronate 3% solution (Viscoat, Alcon Laboratories) after small-incision cataract surgery increases IOP at postoperative days 1 and 2, but not at any later postoperative days for up to 1 month (104452).
• Osteoarthritis. Chondroitin sulfate seems to modestly reduce osteoarthritis pain and improve function. Pharmaceutical-grade chondroitin sulfate products have shown the most benefit. Details: Meta-analyses of randomized controlled trials in patients with mostly knee osteoarthritis show that taking chondroitin sulfate 800-2000 mg in single or divided doses daily for at least 3 months modestly reduces pain and disability when compared with placebo. However, included studies were heterogeneous and most had high attrition bias. A sub-group analysis of high-quality studies shows that 16 patients need to take chondroitin sulfate for 6 months for one patient to experience at least a 20% reduction in pain (94381,95792,99685,104446). When compared with conventional treatments like diclofenac 50 mg three times daily, chondroitin sulfate improves symptoms more slowly; however, the improvement seems to persist for up to 3 months after treatment cessation (322). Chondroitin also seems to have disease-modifying benefits. Clinical research in patients with osteoarthritis of the knee or hip shows that taking chondroitin sulfate 800 mg daily or more for 2 years might modestly reduce joint degeneration and narrowing when compared with placebo or celecoxib (42348,42398,94381,95516). Overall, most of the positive research involved pharmaceutical-grade chondroitin sulfate products, which are available as prescription products in some countries, such as Chondrosulf (IBSA Institut Biochimique SA) (17732,42348,42398,42536,89596,94360,104446), Chondrosan (Bioibérica, S.A.) (42463,42513), and Structum (Laboratoires Pierre Fabre) (22212,42520,89593). One clinical study shows that taking a pharmaceutical-grade chondroitin product (Chondrosulf) 800 mg daily seems to be comparable to taking celecoxib 200 mg daily for reducing pain and improving knee function (94360). Pharmaceutical-grade chondroitin products might demonstrate greater benefit due to higher quality (94360,102116). It is also important to note that most clinical studies using pharmaceutical-grade products are manufacturer-funded (94381). Furthermore, they may not be readily available for purchase in the US. Experts have conflicting stances on the use of chondroitin for osteoarthritis. The American College of Rheumatology (ACR) strongly recommends against the use of chondroitin for any form of osteoarthritis (102114). Conversely, the European Society of Clinical and Economic Aspects of Osteoarthritis (ESCEO) strongly recommends for the use of pharmaceutical-grade chondroitin products. Additionally, the ESCEO provides a weak recommendation against the use of chondroitin in combination with glucosamine (102141). These differing recommendations seem to be related to interpretation of the evidence for pharmaceutical-grade products. The ACR has determined that the inconsistent evidence may indicate the presence of industry bias; the ESCEO has determined that the inconsistent evidence is due to inconsistent product quality. Chondroitin is often used in combination with glucosamine and/or other products. Long-term studies in patients with osteoarthritis show that taking non-branded chondroitin sulfate with glucosamine sulfate modestly reduces joint-space narrowing when compared with control (89558,94380,95792). However, meta-analyses and individual clinical studies assessing non-branded preparations of chondroitin sulfate with glucosamine hydrochloride or glucosamine sulfate do not show reduced pain in patients with knee osteoarthritis when compared with control (13579,89558,95788,99683,99685). In contrast, pain reduction was reported for branded formulations such as chondroitin sulfate with glucosamine hydrochloride and manganese ascorbate (Cosamin DS, Nutramax Laboratories) (4237,7169); chondroitin sulfate with glucosamine hydrochloride (Droglican, Bioiberica, S.A.) (89516); or chondroitin sulfate with collagen peptides and hyaluronic acid (BioCell Collagen, BioCell Technology, LLC) (28678,28680). A large, prospective observational study in adults with knee or hip osteoarthritis suggests that taking glucosamine hydrochloride 500 mg and chondroitin sulfate 400 mg (Theraflex, Bayer) three times daily for the first 3 weeks, then twice daily thereafter for up to 64 weeks, is associated with reductions in pain, stiffness, and the need for concomitant analgesic therapy, and improvements in daily function and knee- or hip-related quality of life, when compared to baseline. The most pronounced improvements are from 16-24 weeks (111647). It is unclear if the benefit seen with these specific products is due to bias introduced by industry funding or due to higher quality. Limited research has also evaluated INTRAMUSCULAR and TOPICAL chondroitin. Some clinical research shows that receiving daily intramuscular injections of chondroitin sulfate for 6 months improves pain and function in patients with osteoarthritis (42396,42397). A topical preparation of chondroitin sulfate in combination with glucosamine sulfate, shark cartilage, and camphor also seems to reduce arthritis symptoms. However, any symptom relief is most likely due to the counterirritant effect of camphor and not the other ingredients (10327). There is no research showing that chondroitin is absorbed topically.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Oral chondroitin sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in females with aging skin shows that taking a specific combination product (BioCell Collagen, BioCell Technology, LLC) containing chondroitin sulfate 200 mg, collagen peptides 600 mg, and hyaluronic acid 100 mg daily for 12 weeks reduces lines and wrinkles by about 13% when compared with baseline (28681). The validity of these findings is limited by the lack of a comparator group. It is also unclear if these improvements are due to chondroitin sulfate, other ingredients, or the combination. Furthermore, it should be noted that this study was funded by the product manufacturer.
• Aromatase inhibitor-induced arthralgia. Oral chondroitin sulfate has only been evaluated in combination with glucosamine sulfate; its effect when used alone is unclear. Details: A small open-label clinical study in postmenopausal females with early stage breast cancer shows that taking a combination of glucosamine sulfate 1500 mg and chondroitin sulfate 1200 mg in 2-3 divided doses daily for 24 weeks improves pain and symptoms associated with aromatase inhibitor-induced arthralgias when compared to baseline (89561). The validity of this finding is limited by the lack of a control group.
• Cancer. Some low-quality observational studies suggest that oral chondroitin use is not associated with a lower risk of cancer. Details: A meta-analysis of observational research has found that use of chondroitin with or without glucosamine is not associated with a lower risk of cancer when compared with no use (110625).
• Colorectal adenoma. Oral chondroitin has only been evaluated in combination with glucosamine; its effect when used alone is unclear. Details: An observational study in older adults has found that taking oral chondroitin and glucosamine is associated with a 26% reduced chance of high-risk adenoma and 10% reduced chance of conventional adenoma when compared with not using these supplements. This benefit was not seen in a subgroup of younger females (104444).
• Dry eye. It is unclear if ophthalmic chondroitin sulfate improves dry eye symptoms. Details: A small clinical study in patients with dry eye suggests that administering an ophthalmic preparation of chondroitin sulfate every two hours while awake for 2 weeks seems to improve symptoms when compared to baseline (1974). Chondroitin has also been used in combination with other ingredients. A large clinical trial in patients with mild to moderate dry eye disease shows that applying preservative-free eye drops containing chondroitin sulfate with sodium hyaluronate (Humylub Ofteno PF, Laboratorios Sophia), one drop into each eye four times daily for 90 days, seems to be no different for improving dry eye severity when compared with using polyethylene/propylene glycol eye drops (Systane Ultra, Alcon Laboratories) (104443). Another small clinical trial in patients with mild to moderate dry eye shows that using specific eye drops containing chondroitin sulfate and xanthan gum (PRO-148, Laboratorios Sophia) four times daily for 60 days does not improve tear stability, but might improve dry eye severity, when compared with using polyethylene/propylene glycol eye drops (Systane, Alcon Laboratories) (89591).
• Exercise-induced muscle soreness. It is unclear if oral chondroitin sulfate improves muscle soreness from exercise. Details: Preliminary clinical research in untrained males shows that taking chondroitin sulfate 1800 mg twice daily for 14 days before exercise does not reduce post-exercise muscle soreness when compared with placebo (42352). However, another small clinical study in healthy, recreationally active adults shows that a specific combination product (BioCell Collagen, BioCell Technology, LLC) containing chondroitin sulfate 300 mg, collagen peptides 900 mg, and hyaluronic acid 150 mg, taken twice daily for 6 weeks prior to two bouts of resistance exercise, attenuates muscle damage and decreases delayed-onset muscle soreness when compared with placebo (96301). It is unclear if these effects are due to chondroitin sulfate, the other ingredients, or the combination.
• Gastroesophageal reflux disease (GERD). Oral chondroitin sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Patients with non-erosive GERD are thought to be less responsive to conventional acid suppression with proton pump inhibiters (PPIs) and H-2 blockers. A small preliminary clinical study shows that taking a syrup containing hyaluronic acid and chondroitin sulfate along with PPIs, H2-receptor antagonists, and/or antacids, reduces the intensity of symptoms associated with non-erosive GERD by about 3.5-fold when compared with placebo (89592). A larger clinical study in patients with non-erosive GERD shows that taking the same combination agent (Esoxx by Alfa Wassermann) in addition to acid suppression with PPIs improves GERD symptom severity by 21%, heartburn by 15%, and regurgitation by 10% when compared with PPIs with a placebo (101271). This product is available in Canada as EsopH (Exzell Pharma). It is unclear if the benefit of this combination product is due to chondroitin sulfate, hyaluronic acid, or the combination. Chondroitin sulfate has also been evaluated in patients with GERD who experience extraesophageal symptoms. A small clinical study in patients reporting symptoms of cough, hoarseness, postnasal drip, sore throat, and/or throat clearing shows that taking a specific combination product (Gerdoff, SOFAR S.p.A.) containing chondroitin sulfate, hyaluronic acid, and aluminum hydroxide three times daily with omeprazole 40 mg once daily for 6 weeks does not reduce overall symptom scores, based on the Reflux Symptoms Index (RSI) score, when compared with omeprazole alone. However, it does increase the probability of treatment response, defined as a 50% or greater improvement in RSI score, by nearly 40% (109648). This product is available in Italy. It is unclear if these findings are due to chondroitin sulfate, other ingredients, or the combination.
• Gastritis. Oral chondroitin sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with gastritis shows that taking a specific liquid product (Esoxx, Alfa Wasserman Spa) containing chondroitin sulfate and hyaluronic acid four times daily for 4 weeks modestly reduces upper abdominal pain when compared with placebo (99687). It is not clear if this effect is due to chondroitin sulfate, hyaluronic acid, or the combination.
• Hyperlipidemia. Although there is interest in using oral chondroitin for hyperlipidemia, there is insufficient reliable information about the clinical effects of chondroitin for this condition.
• Interstitial cystitis. Small clinical studies suggest that intravesical chondroitin sulfate may not improve interstitial cystitis symptoms. Oral chondroitin sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Several uncontrolled, open-label studies suggest that intravesical chondroitin sulfate, with or without hyaluronic acid, improves clinical symptoms of interstitial cystitis and reduces the problems caused by symptoms in these patients (42338,42371,42373,42385,42387). However, in controlled clinical trials, intravesical chondroitin sulfate 2%, instilled weekly for 6-7 weeks, does not significantly improve symptoms when compared with a placebo solution (42473,42517). Furthermore, a meta-analysis of clinical research shows that intravesical chondroitin sulfate with hyaluronic acid does not improve pain due to interstitial cystitis better than using hyaluronic acid solution alone (97054). Oral chondroitin has been evaluated in combination with other ingredients. Preliminary clinical research shows that taking a specific product (CystoProtek, Tischon Corporation) containing glucosamine sulfate 120 mg, sodium hyaluronate 10 mg, chondroitin sulfate 150 mg, quercetin 150 mg, and rutin 20 mg, as two capsules twice daily for 12 months, reduces symptoms of interstitial cystitis by 44% to 52% (42391). It is not clear if this effect is due to chondroitin, other ingredients, or the combination.
• Kashin-Beck disease. It is unclear if oral chondroitin sulfate improves Kashin-Beck disease symptoms such as pain. Details: A small clinical study in Chinese adults with Kashin-Beck disease shows that taking chondroitin sulfate 600 mg twice daily with or without glucosamine hydrochloride 480 mg three times daily for 6 months decreases pain and stiffness when compared with placebo (42516).
• Osteoporosis. Although there is interest in using oral chondroitin for osteoporosis, there is insufficient reliable information about the clinical effects of chondroitin for this condition.
• Overall mortality. Oral chondroitin has only been evaluated in combination with glucosamine; its effect when used alone is unclear. Details: A cross-sectional observational study suggests that using oral chondroitin and glucosamine for at least one year is associated with a 27% lower incidence of overall mortality and 58% lower incidence of cardiovascular mortality when compared with not using these supplements (104445). However, this study did not clarify the forms of chondroitin and glucosamine used, or the doses, frequencies, or durations of use. Furthermore, the adults that reported glucosamine and chondroitin use also reported overall healthier lifestyle habits than those that were not taking glucosamine and chondroitin. Another observational study suggests that regular use of chondroitin with glucosamine for an average of 8 years is associated with a 30% lower risk of mortality when compared with no use. However, when these findings are adjusted for differences in age, body mass index, and comorbidities, overall mortality risk does not seem to be reduced with chondroitin and glucosamine supplementation (110626). Higher quality, prospective research is needed to clarify the relationship, if any, with overall mortality. Additionally, it is unclear if the effects on mortality are due to chondroitin, glucosamine, or the combination.
• Psoriasis. It is unclear if oral chondroitin sulfate is beneficial for reducing psoriasis disease severity. Details: A clinical study in patients with plaque psoriasis and knee osteoarthritis shows that taking chondroitin sulfate (Condrosan, CS Bio-Active, Bioibérica S.A.) 800 mg daily for 3 months does not appear to reduce the extent or severity of plaque psoriasis when compared with placebo (42463).
• Stroke. It is unclear if oral chondroitin sulfate is beneficial for reducing stroke risk. Details: An observational study in Spanish patients found that chondroitin sulfate use is associated with 23% lower odds of ischemic stroke when compared with non-use; however, the benefit was only observed in patients taking at least 800 mg for no more than one year (109643).
• Temporomandibular disorders (TMD). Oral and topical chondroitin sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of two small clinical studies in patients with TMD shows that taking chondroitin sulfate 1200 mg and glucosamine sulfate 1500 mg daily for 2 months does not reduce pain or increase maximum mouth opening when compared with tramadol 50-100 mg daily (109647). Another small clinical trial in children aged 10-13 years with class II malocclusion shows that application of a specific combination gel product containing glucosamine, chondroitin, and essential oils (Jointace Gel, Vitabiotics) with an expander device twice daily for 3 months does not improve pain, tension, or temporomandibular space measures when compared with placebo (110629).
• Urinary incontinence. Although there is interest in using intravesical chondroitin for urinary incontinence, there is insufficient reliable information about the clinical effects of chondroitin for this condition.
• Urinary tract infections (UTIs). It is unclear if intravesical administration of chondroitin sulfate alone is beneficial in patients with recurrent UTIs. Most research has evaluated the effects of chondroitin sulfate in combination with hyaluronic acid, with promising results. Details: One small observational study in patients with recurrent UTIs has found that intravesical administration of 40 mL of chondroitin sulfate 0.2% weekly for 6 weeks, then every 2 weeks for 2 months, then every 3 weeks for 2 months, and finally every 6 weeks for a total treatment duration of 1 year is associated with a lower number of UTIs and urologist visits when compared with low-dose long-term antibiotic therapy (109649). Most research on the use of chondroitin sulfate for UTIs has evaluated its effects when used in combination with hyaluronic acid. Several small clinical studies and a pooled analysis of the available clinical research show that intravesical administration of 50 mL of specific solutions containing chondroitin sulfate 2% and hyaluronic acid 1.6% (iAluRil, IBSA Farmaceutici; Cystistat, Bioniche) for up to 6 months reduces the rate of UTI recurrence by about 2-3 incidents per year and delays the time to the first UTI recurrence when compared with placebo or prophylaxis with sulfamethoxazole-trimethoprim (42511,42519,89590,89594,99688). However, the validity of these findings is limited by the low quality and high heterogeneity of the included studies, as well as concerns for publication bias (99688). More evidence is needed to rate chondroitin sulfate for these uses.

(Read more about CHONDROITIN SULFATE)

POSSIBLY EFFECTIVE

• Aging skin. Oral collagen peptides seem to improve skin hydration and elasticity in older adults. However, it is unclear if any improvements related to wrinkles are cosmetically important. Details: Meta-analyses of the available research, as well as multiple individual clinical studies, show that collagen peptide products, taken in doses of 372 mg to 12 grams daily for 4-12 weeks, improve skin hydration and elasticity in older adults. Studied products include Peptan-F or Peptan-P (Rousselot), Wellnex (Nitta Gelatin), Gold Collagen Active (Minerva Research Labs), VERISOL (Gelita AG), and Nippi peptide FCP-EX (Nippi/Shizuoka) (97632,100703,101597,104647,107460,112457). Pooled study results also suggest that hydrolyzed collagen sourced from fish improves skin hydration and elasticity, while collagen peptides originating from chickens seems to modestly improve skin elasticity but not hydration. Collagen peptides derived from bovine do not seem to improve skin hydration or elasticity (112457). Despite research showing improvement in skin hydration and elasticity, it is unclear if collagen peptides reduce skin wrinkles to a cosmetically significant degree, as most studies have not evaluated this outcome. In one clinical study, taking a freshwater fish-derived collagen peptide (Vinh Wellness Collagen, Vinh Hoan Corporation) 10 grams every morning reduced wrinkle count in the nasolabial region of the right side, but not the left side, of the face by 24% when compared with placebo. Collagen peptides did not improve participant-reported measures of wrinkles, elasticity, hydration, and others, when compared with placebo (104639). Another clinical study shows that taking a specific fish scale-derived collagen peptide (Wellnex, Nitta Gelatin) with either a high or low ratio of prolyl-hydroxyproline and hydroxylpropyl-glycine as 5 grams orally daily for 8 weeks modestly improves wrinkle depth and roughness, but not wrinkle volume, when compared with placebo. The product with a high ratio of dipeptides had a larger effect (97632). Also, one clinical study shows that taking a specific product containing porcine collagen type I peptides (VERISOL, Gelita AG) 2.5 grams daily for 8 weeks reduces eye wrinkle volume by 20% when compared with placebo (101648). Two similar moderate-size clinical studies in middle-aged adults with crow's feet wrinkles and dry skin show that taking specific low-molecular-weight fish-derived collagen peptide products (Geltech Co.; CPNS) at doses of 2000 mg or 1650 mg, respectively, daily for 12 weeks improves eye wrinkles, skin hydration, and elasticity when compared with placebo (110729,110730). While investigator satisfaction scores regarding wrinkle reduction were modestly improved, participant satisfaction was not improved (110729). Small clinical studies have shown contradictory findings when collagen peptides are taken in combination with other ingredients. In one clinical trial, a specific drink (Diva Luxe) providing fish collagen peptides 5.5 grams plus Chenopodium formosanum extract 1 gram daily for 8 weeks improved some measures of skin brightness and hydration, but not wrinkles and crow's feet, when compared with placebo (104646). Another small clinical study shows that taking collagen peptides 4 grams daily in combination with coenzyme Q10 50 mg, vitamin C, vitamin A, and biotin for 12 weeks reduces wrinkles and improves skin smoothness by a small amount when compared with placebo. However, there was no difference in skin elasticity or hydration (104638). A clinical study in older females shows that taking collagen peptides 9 grams in combination with zinc and vitamins A, C, and E daily for 90 days increases stratum corneum water content and skin viscoelasticity when compared with placebo. However, it is unclear if the improvement from baseline differed between groups. Small improvements in dermal echogenicity, wrinkles, or skin pores were noted in some facial regions, but the lack of statistical comparison to placebo limits the validity of these findings (107464). Some small clinical studies have shown mixed effects with low doses of collagen peptides from preliminary clinical research using BioCell Collagen (BioCell Technology, LLC) or Celergen (Laboratories-Dom) (28681,97930). It is unclear if any improvements from these studies are due to collagen peptides, other ingredients, or the combinations. Topical application of collagen peptides has been minimally evaluated. A very small observational study in older adults has found that application of a carbopol gel containing collagen peptides 1% to the periorbital area twice daily for 8 weeks is associated with increased skin hydration and elasticity and reduced transepidermal water loss, skin roughness, and wrinkles when compared with baseline (107459). The validity of these findings is limited by poor study methodology, lack of statistical comparison to baseline, and lack of a comparator group.
• Dry skin. Oral collagen peptides seem to improve skin hydration and elasticity in adults with dry skin. However, their effect on other measures of dry skin is unclear. Details: A meta-analysis of 19 clinical studies, along with several small and moderate-sized individual studies, some of which are included in the meta-analysis, show that taking collagen peptides 372 mg to 12 grams daily for 4-12 weeks improves skin hydration and elasticity when compared with placebo in healthy adults (107461,110729,110730,112457,112458). Some studies show that collagen peptides improve skin roughness (107461), decrease peeling (110729,110730), and increase stratum corneum and epidermis water content (107462) but not skin gloss (107461) or elasticity (107462). Some research shows that collagen peptides reduce transepidermal water loss (107462), while another study shows no change (107461). Subgroup analysis of the meta-analysis suggests that hydrolyzed collagen sourced from fish improves skin hydration and elasticity the most, while collagen peptides originating from chicken seem to modestly improve skin elasticity but not hydration. Collagen peptides from bovine do not seem to improve skin hydration or elasticity (112457). Studied products include FCP-Z (Nippi Co., Ltd), Geltech Co., CPNS, and GPVGPS Collagen (Daehan Chemtech) (107462,110729,110730,112458). Collagen peptides have also been evaluated in combination with other ingredients. A small clinical study in healthy adults with low skin moisture shows that drinking 30 mL of a beverage containing fish scale-derived collagen peptides 10 grams and ornithine 400 mg (FUJIFILM) daily for 8 weeks does not improve skin moisture but seems to improve skin elasticity and reduce water loss when compared with placebo (101607). Another very small clinical study in a mixed population of patients with dry skin and mild atopic dermatitis shows that twice daily application of an emollient containing collagen peptides, soluble proteoglycan, and hyaluronic acid for 4 weeks reduces itching severity from moderate at baseline to mild or almost none. Transepidermal water loss and skin hydration also improved when compared to baseline (107465). The validity of these findings is limited by the lack of a comparator group. Both of these studies are limited by their small size, and it is unclear if any improvements are due to collagen peptides, other ingredients, or the combination.

POSSIBLY INEFFECTIVE

• Muscle strength. Most research suggests that oral collagen peptides do not improve leg strength. However, they may improve hand-grip strength and fat-free mass. Details: Small clinical studies in healthy male and female athletes or non-athletes undergoing resistance or other training show that taking collagen peptides 15-30 grams daily or after training sessions for up to 15 weeks, with or without vitamin C, does not improve leg strength (i.e. squat strength, knee extension, or flexor strength) when compared with placebo (101608,104641,107457,110668,110669). Similarly, 2 very small clinical studies in healthy adults show that taking a specific oral collagen peptide product (Bodybalance, Gelita AG) 5-15 grams daily while completing a resistance training program for 14-15 weeks increases patellar tendon cross-sectional area but does not improve most measures of tendinous tissue remodeling including patellar tendon size, vastus lateralis aponeurosis size, patellar tendon mechanical properties, tendon stiffness, maximal knee extension strength, or rectus femoris muscle cross-sectional area when compared with placebo (112452,112454). However, a small clinical study with the same product in untrained females aged 18-50 years shows that taking 15 grams daily in addition to resistance training three times weekly for 12 weeks improves hand-grip strength when compared with resistance training and placebo (101608). In untrained males aged 30-60 years, taking the same dose of this collagen peptide product along with resistance training for 12 weeks improves fat-free mass by 3 kg, compared with 2 kg with resistance training and placebo. A post-hoc exploratory analysis suggests that the effects seen in males are similar to those seen with whey protein (107457).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there has been interest in using oral collagen peptides for acne, there is insufficient reliable information about the clinical effects of collagen peptides for this condition.
• Androgenic alopecia. Oral collagen peptides have only been evaluated in combination with other ingredients, their effect when used alone is unclear. Details: A moderate-sized clinical study in adults with androgenic alopecia or telogen effluvium shows that taking a combination product containing hydrolyzed collagen 300 mg, taurine, cysteine, methionine, iron, and selenium (GFM Oral, Cantabria Labs) daily along with conventional therapy, consisting primarily of finasteride or minoxidil, for 12 weeks improves hair loss when compared with conventional therapy alone (111636). It is unclear if this effect is due to collagen peptides, other ingredients, or the combination.
• Athletic performance. It is unclear if oral collagen peptides improve performance in most athletes. Details: In recreationally active female runners undergoing resistance and endurance training 3 times weekly, clinical research shows that taking collagen peptides 7.5 grams twice daily for 12 weeks increases running distance by approximately 1,034 meters, compared with an increase of 703 meters in those taking placebo, although there was no effect on speed (104641). A clinical study in healthy young male athletes undergoing heavy strength and power training shows that taking collagen peptides 20 grams and vitamin C 50 mg daily for 3 weeks improves squat performance and countermovement jump performance when compared with placebo. However, removal of a single outlier negated the statistical significance of most of these findings (107456). Also, it is unclear if any improvements from this study are due to collagen peptides, vitamin C, or the combination.
• Atopic dermatitis (eczema). It is unclear if oral or topical collagen peptides are beneficial for improving the severity of eczema. Details: A small clinical study in patients with atopic dermatitis shows that taking a porcine skin-derived collagen peptide with a high ratio of tripeptides with glycine-X-Y sequences, 3.9 grams daily for 12 weeks, improves symptoms and severity of eczema when compared to baseline. There was no improvement in the group taking the same dose of porcine skin-derived collagen peptide without the high ratio of tripeptides (101605). Another very small clinical study in a mixed population of patients with atopic dermatitis and dry skin shows that twice daily application of an emollient containing collagen peptides, soluble proteoglycan, and hyaluronic acid for 4 weeks reduces itching severity from moderate at baseline to mild or almost none. Transepidermal water loss and skin hydration also improved when compared to baseline (107465). It is unclear if any improvements are due to collagen peptides, the other ingredients, or the combination. Both of these studies are limited by their small size and lack of comparator groups.
• Burns. Some preliminary clinical research suggests that oral collagen peptides might reduce the time needed for burn healing. Details: In male patients with 20% to 30% body surface area burns, a small clinical trial shows that taking a collagen-based supplement providing collagen peptides (Amutiya, Qom) 36 grams daily for 4 weeks improves wound healing when compared with taking an isocaloric supplement containing the same amount of soy protein. Complete wound healing occurred in 50% and 100% of patients taking collagen for 2 and 4 weeks, respectively, compared with 7% and 40% of those taking the isocaloric product. The duration of hospital stay was not significantly different between the two groups (104642). A small clinical study in hospitalized adults with 20-45% body surface area 2nd or 3rd degree burns shows that consuming a beverage containing collagen peptides 40 grams daily for 4 weeks shortens the time to wound healing, improves scar scores, and reduces the duration of hospital stays but does not limit wound infections when compared with placebo. Adding fish oil 3 grams daily did not further improve outcomes (110667).
• Brittle nails. One small clinical study suggests that oral collagen peptides may improve nail health in people with brittle nails. Details: A small clinical study shows that taking a specific porcine type I collagen peptide product (VERISOL, Gelita AG) 2.5 grams daily for 6 months improves overall symptoms of brittle nail syndrome, increases nail growth rate by 12%, and reduces broken nail frequency by 42% when compared with baseline (101606). This study was limited by its small size and lack of a comparator group.
• Cellulite. One small clinical study suggests that oral collagen peptides may reduce cellulite. Details: In people with cellulite, a small clinical study shows that taking specific collagen peptides (VERISOL by Gelita AG) 2.5 grams daily for 6 months seems to reduce cellulite, skin waviness, and dermal density by a small amount when compared with placebo (101619).
• Cognitive function. It is unclear if oral collagen peptides are beneficial for improving memory. Details: In healthy adults, preliminary clinical research shows that taking collagen peptides 5 grams daily for 4 weeks improves some measures of memory and verbal learning when compared to baseline (104643). This study was limited by its small size and lack of a comparator group.
• Dermatoporosis. One small clinical study suggests that using oral or topical collagen peptides does not improve this condition. Details: A small clinical study in post-menopausal patients aged 70 years on average with mild dermatoporosis shows that taking collagen peptides 5 grams daily, applying a collagen peptides 2.5% serum 3 pumps nightly to each forearm, or using these in combination for 6 months does not improve skin lesions, epidermal thickness, collagen or elastin density, or patient perception of skin improvement when compared with placebo (110731). However, it is unclear if these results apply to patients with more severe dermatoporosis.
• Diabetes. Some preliminary clinical research suggests that oral collagen peptides might have a small effect on glycemic indices. Details: Preliminary clinical research in patients with type 2 diabetes shows that taking fish-derived collagen peptides 6.5 grams orally twice daily for 3 months, in addition to treatment with antidiabetes drugs, may modestly reduce levels of fasting blood glucose, glycated hemoglobin, and fasting blood insulin and may increase levels of insulin sensitivity when compared with antidiabetes drugs and placebo (101626,101627).
• Erythema. It is unclear if oral collagen peptides are beneficial for erythema. Details: A moderate-sized clinical study in adults with dry and wrinkled eye skin shows that taking low-molecular weight collagen peptides (GPVGPS Collagen, Daehan Chemtech) 2000 mg daily for 12 weeks reduces erythema index when compared with placebo (112458).
• Exercise-induced gastrointestinal (GI) symptoms. It is unclear if oral collagen peptides prevent GI symptoms due to exercise. Details: A small crossover study in moderately well-trained young adults shows that taking collagen peptides 10 grams daily for 7 days prior to rigorous treadmill exercise does not limit GI symptoms but may attenuate some markers of GI distress when compared with placebo (110665).
• Exercise-induced muscle soreness. It is unclear if oral collagen peptides prevent muscle soreness after exercise. Details: Preliminary clinical research in a small number of healthy, recreationally active adults shows that taking collagen peptides (Peptan, Rousselot BVBA, Collagen Peptides, Vital Proteins) 10-15 grams twice daily, starting 7 days prior to strenuous exercise and continuing for 2-5 days after, does not reduce muscle soreness when compared with placebo (100700,104648). However, there was a small benefit on the recovery of countermovement jump ability within 24 hours (104648). Furthermore, another small clinical study in adults unaccustomed to exercise shows that taking collagen peptides 10 grams daily for 33 days modestly reduces muscle soreness and fatigue immediately after the exercise load, but not 2 hours after exercise or the next morning, when compared with placebo (111639). Also, a small clinical study in active middle-aged adults shows that taking specific collagen peptides (SOLUGEL Collagen Peptides, PB Leiner) 10 grams daily for 6 months improves pain in those who exercise frequently (>188 minutes weekly) when compared with placebo. However, collagen peptides do not seem to improve pain in low frequency exercisers (<188 minutes weekly) (112455). Collagen peptides have also been evaluated in combination with other ingredients. One preliminary clinical study in healthy, recreationally active adults shows that taking a specific product (BioCell Collagen, BioCell Technology, LLC) containing collagen peptides from chicken collagen type II, hyaluronic acid, and chondroitin sulfate 1.5 grams twice daily for 6 weeks prior to two bouts of intense resistance exercise attenuates increases in biomarkers of muscle damage and decreases delayed onset muscle soreness when compared with placebo (96301). It is unclear if these benefits are due to collagen peptides, other ingredients or the combination.
• Gingivitis. It is unclear if oral collagen peptides are beneficial for patients with gingivitis. Details: A small clinical study in patients with mild-to-moderate chronic gingivitis shows that taking a specific collagen peptide product (Verisol B, Gelita AG) 5 grams daily for 90 days following mechanical plaque removal reduces bleeding and inflammation but does not improve plaque scores when compared with placebo (110666).
• Hypertension. Limited research suggests that oral collagen peptides may lower systolic or diastolic blood pressure. However, results are inconsistent. Details: One preliminary clinical study in patients with hypertension and type 2 diabetes shows that taking fish-derived collagen peptides 6.5 grams twice daily for 3 months modestly reduces diastolic, but not systolic, blood pressure when compared with placebo (101626). Another small clinical study in patients with mildly elevated blood pressure shows that taking a test food containing chicken leg-derived collagen peptides 2.9 grams daily for 12 weeks lowers systolic, but not diastolic, blood pressure when compared with placebo (101610). An additional small clinical study in patients with mild hypertension shows that taking chicken leg-derived collagen peptides 5.2 grams daily 4 weeks reduces systolic blood pressure by 12 mmHg when compared with baseline (101618). This study was limited by its small size and lack of a comparator group. The reasons for conflicting data are unclear.
• Insomnia. It is unclear if oral collagen peptides are beneficial for insomnia. Details: A very small clinical study in physically active males with difficulty sleeping shows that taking collagen peptides 15 grams before bedtime for 7 nights reduces the frequency of nocturnal awakenings and improves cognitive accuracy but does not improve objective measures of total sleep time, latency, efficiency, stage changes, waking after sleep onset, other cognitive function measures, or subjective measures of sleepiness, fatigue, and sleep quality when compared with placebo (112459).
• Joint pain. Most research shows that oral collagen peptides might moderately reduce joint pain in young athletes. However, evidence in elderly patients is conflicting. Details: Preliminary clinical research in student athletes with joint pain shows that taking a specific collagen peptide product (FORTIGEL, Gelita AG) 10 grams in 25 mL of liquid daily for 24 weeks modestly improves pain during movement and at rest when compared with placebo (101601). Other clinical research in young adults exercising or participating in sports at least 3 hours weekly with activity-related knee pain shows that taking this same product 5 grams daily for 12 weeks reduces pain intensity during activity by 38% to 41%, compared with a 26% to 28% reduction in those taking placebo. However, there was no improvement in pain at rest or after the activity when compared with placebo (97623,107454). Furthermore, it is not clear if these effects are clinically significant. Research on the use of collagen peptides in older patients is conflicting. A small clinical study in otherwise healthy patients aged 40-65 years with joint discomfort shows that taking a specific collagen peptides product (AVC-H2, Avicenna) 1.25 grams twice daily for 8 weeks improves overall Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores by 37% at 4 weeks, compared with 14% in those receiving placebo. However, this difference in improvement was no longer significant at 8 weeks. Collagen peptides also improved the physical activity and stiffness subdomains, but not the pain subdomain, at 4 and 8 weeks when compared with placebo (107455). A larger clinical study in patients 50 years or older with general joint pain shows that taking a specific collagen peptides product (Genacol) 1200 mg daily for 6 months does not reduce pain or improve function when compared with placebo (97657). However, collagen peptides used in combination with other ingredients have shown benefit. Preliminary clinical research in patients 51-70 years of age shows that taking a specific combination product (Gold Collagen Active, Minerva Research Labs) containing fish collagen peptides 4 grams, glucosamine hydrochloride 1000 mg, chondroitin sulfate 500 mg, L-carnitine 200 mg, and other ingredients daily for 90 days reduces joint pain by 43% when compared with baseline, while patients taking placebo saw negligible improvement in pain. A greater percentage of patients taking this product also perceived improvements in joint discomfort, flexibility, mobility, and rigidity when compared with placebo (100703). It is unclear if these effects are due to collagen peptides, other ingredients, or the combination.
• Obesity. It is unclear if oral collagen peptides are beneficial for weight loss. Details: A preliminary clinical study in adults with overweight shows that taking skate skin-derived collagen peptides 2 grams daily for 12 weeks modestly reduces body fat mass by 1.2 kg, compared with an increase of 0.3 kg in the placebo group (101621). It is unclear if collagen peptides improve weight loss or reduce body fat mass in the long-term.
• Osteoarthritis. Most research suggests that oral collagen peptides improve pain in patients with knee osteoarthritis; however, any improvement is modest and may not be considered clinically significant. Details: A meta-analysis of 3 clinical studies, all of which are included below, in adults with knee osteoarthritis shows that taking collagen peptides or hydrolyzed collagen reduces pain when compared with placebo (112456). Clinical research shows that taking specific collagen peptides (Colnatur, Protein SA) 10 grams daily for 5 months increases the number of patients who experience at least a 30% improvement in pain by approximately 42% when compared with placebo. However, there is no difference between groups when the Western Ontario and McMaster Universities (WOMAC) scale is used. Patients with the greatest joint deterioration at baseline, as well as those with the lowest dietary meat intake, seemed most likely to experience benefit from collagen peptides (97635). Another small clinical study shows that taking collagen peptides isolated from pork skin and bovine bone (Nitta Gelatin Inc.) 5 grams dissolved in 250 mL water or milk twice daily after food for 13 weeks modestly improves pain when compared with placebo (101611). Another small clinical study in patients over 40 years old shows that taking collagen peptides (Colatech) 10 grams daily for 90 days reduces pain by about 2 points on a 100-point scale, compared with a 0.9-point reduction with glucosamine sulfate 1.5 grams. Ibuprofen use was not affected (101622). One multicenter clinical study shows that taking collagen peptides 10 grams daily for 6 months does not relieve pain or improve joint function when compared with placebo, although a trend towards reduced pain and improved joint function was observed in patients with severe symptoms at baseline (7704). Collagen peptides have also been evaluated in combination with other ingredients. Clinical research in patients with osteoarthritis of the knee, hip, or hand shows that taking a specific product (BioCell Collagen, BioCell Technology, LLC) containing collagen peptides from chicken collagen type II, hyaluronic acid, and chondroitin sulfate 1 gram twice daily for up to 10 weeks reduces pain and the need for rescue analgesics and increases physical activity when compared with placebo (28678,28680). Similarly, a moderate-size clinical study in patients aged 45-75 years with mild to moderate knee osteoarthritis undergoing resistance exercise twice weekly shows that taking a specific product (Suntory Beverage and Food Asia) containing collagen peptides from chicken collagen type II, hyaluronic acid, and chondroitin sulfate 2 grams daily for 24 weeks does not improve WOMAC scores when compared with glucosamine 1.5 grams daily or placebo, but may modestly improve pain scores when compared with placebo. However, the use of rescue analgesics was not assessed. Adding essence of chicken 5.81 grams daily to collagen peptides did not improve WOMAC or pain scores (110670). Also, preliminary clinical research in patients with knee osteoarthrosis shows that taking a specific product (Ialoral 1500, PharmaSuisse Laboratories Srl) containing collagen peptides, chondroitin sulfate, hyaluronic acid, and keratin peptides for 4 weeks improves pain and function by a moderate amount when compared with baseline (104645). However, the validity of these findings is limited by the lack of statistical comparison to the control group. It is unclear if these effects are due to collagen peptides, other ingredients, or the combination.
• Osteopenia. It is unclear if oral collagen peptides prevent loss of bone mineral density (BMD) in postmenopausal adults. Details: A large clinical study in patients with reduced BMD after menopause shows that taking specific collagen peptides (Fortibone, Gelita AG) 5 grams daily for 12 months increases BMD of the spine and the femoral neck by 3% and 7%, respectively, compared with losses of 1% with placebo (101609). In a very small observational extension of this study, BMD continued to increase over an additional 4 years when compared with baseline. However, the validity of these findings is limited by the lack of a comparator group (107340). Collagen peptides have also been evaluated in combination with calcium and vitamin D. In patients with osteopenia after menopause, a small clinical study shows that taking collagen peptides calcium chelate 5 grams, containing elemental calcium 500 mg and vitamin D3 200 IU, daily for 12 months does not affect total hip, total body, or vertebral BMD when compared with calcium 500 mg and vitamin D 200 IU (101604). The validity of these results is limited by a high dropout rate and insufficient power to detect smaller effects. Conversely, another small study in this population shows that taking specific collagen peptides (Fortibone, Gelita AG) in combination with elemental calcium (as calcium lactate) 500 mg and vitamin D3 400 IU daily for 12 months improves trabecular bone mineral content, trabecular volumetric BMD, and cortical volumetric BMD, but not cortical bone mineral content, when compared with a combination tablet containing equivalent doses of elemental calcium (as calcium carbonate) and vitamin D (107453). It is unclear if these effects are due to collagen peptides, other ingredients, or the combination.
• Osteoporosis. It is unclear if oral collagen peptides improve bone mineral density (BMD) in adults with osteoporosis after menopause. Details: In patients with osteoporosis after menopause, clinical research shows that taking collagen peptides 10 grams daily in addition to twice weekly intramuscular calcitonin for 6 months does not improve BMD in the forearm when compared with calcitonin alone (104649). It is unclear if supplementation with collagen peptides improves BMD in the femoral neck or lumbar spine.
• Pressure ulcers. Oral collagen peptides might help to improve ulcer size and healing. Details: A small clinical study in patients with Stage II, III, or IV pressure ulcers shows that taking collagen peptides 5 grams orally three times daily for 8 weeks in addition to standard care improves ulcer size and exudate when compared with placebo and standard care (101612). This study was limited because it only used one scale to assess healing of the pressure ulcer. Another small clinical study in patients with stage II or III pressure ulcers shows that receiving standard care and collagen peptides with high levels of prolyl-hydroxyproline 5 grams twice daily for 16 weeks improves ulcer exudate, healing, and wound size when compared with standard care plus placebo (101620).
• Sarcopenia. Oral collagen peptides might help to increase fat-free mass. However, it is unclear if collagen peptides are more beneficial than other types of protein. Details: A small clinical study in elderly males with sarcopenia shows that taking collagen peptides from type I collagen 15 grams daily for 12 weeks along with three resistance training sessions weekly modestly increases fat-free mass and power when compared with resistance training and placebo (101624). It is unclear if supplementation with collagen peptides is more beneficial than supplementation with protein.
• Sprains. It is unclear if oral collagen peptides improve ankle instability after a previous sprain. Details: A small clinical study in athletes with chronic ankle instability from an ankle sprain shows that taking collagen peptides 5 grams daily for 6 months improves subjective ankle instability when compared with placebo. However, ankle stiffness, which is a more objective measure of ankle instability, is not improved when compared with placebo (101603).
• Tendinopathy. It is unclear if oral collagen peptides improve tendon pain. Details: A small clinical study in patients with Achilles tendinopathy shows that taking a specific collagen peptides supplement (TENDOFORTE, Gelita AG) 2.5 grams daily for 3 months in addition to a calf-strengthening program improves pain when compared with baseline (101615). The validity of this finding is limited by the lack of a comparator group.
• Wound healing. It is unclear if oral collagen peptides improve wound healing. Details: A small clinical study in healthy volunteers with wounds after photothermolysis shows that taking collagen peptides 3 grams daily for 4 weeks improves erythema, skin hydration, and skin elasticity when compared with placebo (101599). This study was limited by small size, short duration, and no direct measurement of wound healing or scar formation.
• Wrinkled skin. Some small clinical studies suggest that oral collagen peptides might help to reduce lines and wrinkles from sun damage. Details: Preliminary clinical research in females with photodamaged skin shows that taking a specific low molecular weight collagen peptide product (Evercollagen, Newtree Co.) 1000 mg daily for 12 weeks modestly improves most measures of skin wrinkling, hydration, and elasticity when compared with placebo. This specific collagen peptide product is standardized to contain more than 15% glycine-containing tripeptides, including 3% glycyl-prolyl-hydroxyproline (100702). Another moderate-sized clinical study in adults with dry and wrinkled eye skin shows that taking low-molecular weight collagen peptides (GPVGPS Collagen, Daehan Chemtech) 2000 mg daily for 12 weeks reduces skin wrinkling parameters including facial skin roughness, peak-to-valley values, maximum wrinkle height, and eye wrinkle volume and improves skin hydration and skin elasticity when compared with placebo. However, there was no improvement in maximum wrinkle depth (112458). Another preliminary clinical study shows that taking a specific combination product (BioCell Collagen, BioCell Technology, LLC) containing collagen peptides from chicken collagen type II 600 mg, low molecular weight hyaluronic acid 100 mg, and chondroitin sulfate 200 mg daily for 12 weeks reduces lines and wrinkles associated with both natural aging and photoaging by about 13% when compared to baseline (28681). This study was limited by the lack of a comparator group. Additionally, it is unclear if these effects are due to collagen peptides, other ingredients, or the combination. More evidence is needed to rate collagen peptides for these uses.

(Read more about COLLAGEN PEPTIDES)

LIKELY EFFECTIVE

• Osteoarthritis. Oral glucosamine sulfate taken for at least 4 weeks is modestly beneficial for improving pain and function in knee osteoarthritis. However, oral glucosamine hydrochloride seems to only be beneficial when used in combination with chondroitin and other ingredients. It is unclear if glucosamine can slow disease progression or improve symptoms in other forms of osteoarthritis. Details: Meta-analyses of the available research in adults with KNEE osteoarthritis show that taking glucosamine SULFATE 1500 mg daily for up to 3 years modestly improves pain and function when compared with placebo (14305,89521,94382,95785,99684). Individual studies show 28% to 41% pain reduction and 21% to 46% improvement in function when compared with placebo (7026,8942,12461,20084,94382). Some research suggests that glucosamine sulfate reduces pain similarly to various non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen 400 mg three times daily and piroxicam 20 mg daily. However, NSAIDs appear to relieve symptoms within 2 weeks, while glucosamine sulfate takes 4-8 weeks. Notably, glucosamine sulfate appears to sustain benefit for longer after treatment withdrawal when compared with piroxicam (2604,20094,20096). Other clinical research shows that glucosamine sulfate 1500 mg once daily for 6 months might be more effective for reducing symptoms than acetaminophen 1 gram three times daily or 650 mg once daily in patients with moderate knee osteoarthritis (13578,20098). However, not all research shows benefit. Small clinical studies suggest that glucosamine sulfate 1500 mg daily for 2-6 months may NOT work for severe, long-standing osteoarthritis (1330,11459). It is unclear if glucosamine sulfate can slow disease progression. A specific crystalline glucosamine sulfate product (Dona, Rotta Pharmaceuticals) taken as 1500 mg daily for up to 3 years seems to prevent joint space narrowing of greater than 0.5 mm by up to 54% when compared with placebo (7026,8942,13719,42420). In contrast, other glucosamine sulfate formulations have not consistently been shown to improve symptoms or prevent joint space narrowing when compared with placebo (14305,89558,94382,95788). It is unclear if the benefit seen with this specific product (Dona) is due to bias introduced by industry funding or due to a higher quality product (42492). Glucosamine products associated with quality concerns have demonstrated inconsistent benefits in research (8128,102116). Limited research on the use of a different salt, glucosamine HYDROCHLORIDE, has found no benefit for knee osteoarthritis. A meta-analysis of clinical research and two other clinical trials show that taking glucosamine hydrochloride 1500 mg daily for up to 18 months does not seem to reduce pain when compared with placebo (18344,89519,89521). However, one small, unblinded clinical study in patients with mild to moderate osteoarthritis shows that taking a combination of glucosamine hydrochloride 480 mg every 12 hours and celecoxib 200 mg daily reduces pain scores, osteoarthritis severity, and inflammatory markers to a greater extent than celecoxib alone (106883). There is mixed evidence of benefit when glucosamine hydrochloride is used with chondroitin. Clinical research in patients over 40 years of age shows that taking a noncommercial preparation of glucosamine hydrochloride 1500 mg daily in combination with chondroitin sulfate 1200 mg daily for 6-24 months does not reduce pain when compared with placebo. The placebo response in these studies was sometimes as high as 60% (13579,14809,42477). However, a large, prospective observational study in adults with knee or hip osteoarthritis suggests that taking glucosamine hydrochloride 500 mg and chondroitin sulfate 400 mg (Theraflex, Bayer) three times daily for the first 3 weeks then twice daily thereafter for up to 64 weeks is associated with reductions in pain, stiffness, and the need for concomitant analgesic therapy and improvements in daily function and knee- or hip-related quality of life when compared to baseline. The most pronounced improvements were from 16-24 weeks (111647). The validity of these effects is limited by subjective outcomes, a lack of control group, and the observational design of the study. Furthermore, another clinical trial shows that taking a prescription product available in Spain (Droglican, Bioibérica S.A.), providing a similar daily dose of glucosamine hydrochloride with chondroitin sulfate for 6 months is non-inferior to celecoxib 200 mg daily for relieving pain, but not stiffness or function (89516). Small clinical studies show that taking a specific combination product (Cosamin or Cosamin DS, Nutramax Laboratories) containing glucosamine hydrochloride 1500-2000 mg, low molecular weight chondroitin sulfate 1200-1600 mg, and manganese ascorbate 228-304 mg, in 2-3 divided doses daily for 2-6 months improves pain in patients with mild or moderate, but not severe, osteoarthritis when compared with placebo (4237,7169). A different combination product (Gurukosamin & Kondoroichin, Suntory Wellness Ltd.) containing glucosamine hydrochloride 1200 mg, chondroitin sulfate 60 mg, and quercetin glycosides 45 mg, taken daily for 16 weeks, also seems to improve symptoms of knee osteoarthritis when compared with placebo (42514). It is unclear if the findings of any of these studies are due to glucosamine, chondroitin, other ingredients, or the combination. Despite evidence suggesting differing benefit (89521,94382), head-to-head comparisons of glucosamine sulfate and glucosamine hydrochloride are limited, and it is not universally acknowledged that these salts have different effectiveness profiles. One large clinical study in patients with knee osteoarthritis shows that taking a specific product (Artrolive, Aché Laboratórios Farmacêuticos S.A.) containing glucosamine sulfate 500 mg and chondroitin sulfate 400 mg three times daily for 4 months seems to be no different for reducing pain when compared with taking glucosamine hydrochloride 500 mg and chondroitin sulfate 400 mg (Cosamin DS, Nutramax Laboratories, Inc.) three times daily (89520). This study was funded by the supplement manufacturer. Many meta-analyses have pooled studies of both glucosamine salts together, producing largely inconsistent results (94381,99683,99685,112444). Experts have conflicting stances on the use of glucosamine. The American College of Rheumatology (ACR) strongly recommends against the use of any glucosamine products for any form of osteoarthritis (102114). Conversely, the European Society of Clinical and Economic Aspects of Osteoarthritis (ESCEO) strongly recommends the use of pharmaceutical-grade glucosamine sulfate products, such as Dona (Rotta Pharmaceuticals), in patients with osteoarthritis. Additionally, the ESCEO provides a weak recommendation against the use of glucosamine in combination with chondroitin (102141). These differing recommendations seem to be related to interpretation of the evidence for pharmaceutical-grade products. The ACR has determined that the inconsistent evidence may indicate the presence of industry bias; the ESCEO has determined that the inconsistent evidence is due to inconsistent product quality. Limited research has found mixed benefit of using glucosamine on osteoarthritis of the SPINE, HIP, or HAND. In one study of patients with osteoarthritis of the lumbar spine, taking glucosamine sulfate (Dona, Rotta Pharmaceuticals) 1500 mg daily for 6 weeks reduced pain in more patients when compared with placebo (1316). However, in another study, using a different glucosamine sulfate product (Glucosamine Sulfate, PharmaNord) 1500 mg daily for 6 months did not reduce pain when compared with placebo (89562). In patients with hip osteoarthritis, taking glucosamine sulfate 1500 mg once daily for 2 years did not reduce symptoms or slow disease progression when compared with placebo (16717,20100); however, there was a high rate of hip replacement, which may have confounded results (16717,16718). In patients with erosive osteoarthritis of the hand, observational research has found that taking glucosamine sulfate (Dona, Rotta Pharmaceuticals) 1500 mg daily along with conventional therapy for 6 months is associated with reduced hand pain, a shorter duration of morning stiffness, and improved hand function when compared with conventional therapy alone (108897). Limited research has also evaluated INTRAMUSCULAR and TOPICAL glucosamine sulfate. A clinical study in patients with mild to moderate knee osteoarthritis (radiological stage I-III) shows that giving intramuscular glucosamine sulfate 400 mg twice per week for 6 weeks reduces the severity of symptoms when compared with placebo (2605). There is also a small study showing that a topical preparation of glucosamine sulfate in combination with chondroitin sulfate, shark cartilage, and camphor reduces osteoarthritis symptoms when compared with placebo. However, any symptom relief is most likely due to the counterirritant effect of camphor and not the other ingredients (10327,12467). There is no evidence that glucosamine is absorbed topically. Glucosamine sulfate does not seem to PREVENT osteoarthritis. Clinical studies in overweight healthy females aged 50-60 years shows that taking crystalline glucosamine sulfate 1500 mg orally daily for 2.5 years does not reduce the incidence of osteoarthritis after a 6-7 year follow-up; however, it may reduce the percentage of patients who experience knee joint space narrowing (95789,97053).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Topical N-acetyl glucosamine has only been evaluated in combination with niacinamide for reducing hyperpigmentation and liver skin spots on aging skin; its effect when used alone is unclear. Details: A clinical study in females ages 40-60 years with skin hyperpigmentation and solar lentigines (liver spots) primarily due to aging and sun exposure shows that applying a cream containing 2% N-acetyl glucosamine and 4% niacinamide to the face twice daily with sunscreen for 10 weeks decreases facial hyperpigmentation when compared with sunscreen alone (92721). The effect of N-acetyl glucosamine alone is unclear.
• Aromatase inhibitor-induced arthralgia. Oral glucosamine sulfate has only been evaluated in combination with chondroitin; its effect when used alone is unclear. Details: A small open-label clinical study in patients with aromatase inhibitor-induced arthralgia shows that taking a combination of glucosamine sulfate 1500 mg and chondroitin sulfate 1200 mg in 2-3 divided doses daily for 24 weeks improves pain when compared to baseline in postmenopausal adults with early stage breast cancer (89561). The validity of this finding is limited by a lack of control group.
• Back pain. Although there is interest in using oral glucosamine for back pain, there is insufficient reliable information about the clinical effects of glucosamine for this condition.
• Cancer. Some low-quality observational studies have inconsistently found that glucosamine may be associated with a lower risk of different cancers; however, better quality evidence is needed. Details: A meta-analysis of observational research has found that use of glucosamine with or without chondroitin is associated with a 7% to 12% lower risk of cancer when compared with no use of glucosamine. A subgroup analysis showed a reduction in the risk of colorectal cancer, but not other types of cancer (110625). Observational research report conflicting relationships between glucosamine and cancer. Some observational research in adults in the United Kingdom has found that taking glucosamine is associated with 4% higher risk of cancer over a median follow up for 13 years. However, a subgroup analysis showed a reduction in the risk of lung cancer (110627). Other observational research in adults in the United Kingdom has found that taking glucosamine is associated with a 5% reduced risk of cancer mortality over a median follow-up of around 12 years, with reductions specifically occurring in those with kidney, lung, and rectal cancers. However, glucosamine use was not linked to a reduced risk of mortality due to bladder, brain, breast, colon, ovarian, prostate, skin, stomach, thyroid, or uterine cancer (109645). These studies are limited by observational designs, which also did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine use also reported overall healthier lifestyle habits than those that were not taking glucosamine. Although some studies attempted to control for these differences, higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and the risk for cancer and/or cancer-related mortality. Of note, some researchers have called into question the results from observational research linking glucosamine use to a lower rate of cancer, claiming that these studies suffer from a high risk of selection bias (109646).
• Cardiovascular disease (CVD). It is unclear if oral glucosamine prevents fatal or non-fatal CVD events. Details: Some observational research of adults in the United Kingdom has found that taking glucosamine is associated with an overall 15% reduced risk for fatal and non-fatal CVD events, including coronary heart disease (CHD) and stroke (99682). However, this study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine use also reported overall healthier lifestyle habits than those that were not taking glucosamine. Conversely, an observational study in Chinese patients with osteoarthritis has found that glucosamine use is associated with a 10% increase in the risk of CVD events and a 12% increase in the risk of CHD, with no increase in the risk of stroke. The risk for these outcomes was greatest in patients with higher adherence to glucosamine and in those taking larger doses (109642). However, this study also did not clarify the form of glucosamine used or provide specifics related to the frequency or duration of use. Furthermore, glucosamine users were generally older, more likely to be on antihyperlipidemic or antiplatelet therapy, and more likely to have multiple comorbidities compared with non-users. Both studies attempted to control for the differences in characteristics between glucosamine users and non-users; despite this, higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and CVD risk.
• Colorectal adenoma. Oral glucosamine has only been evaluated in combination with chondroitin; its effect when used alone is unclear. Details: An observational study in older adults has found that taking glucosamine and chondroitin is associated with a 26% reduced risk of high-risk adenoma and 10% reduced risk of conventional adenoma when compared with not using these supplements. This benefit was not seen in a subgroup of younger females (104444). This study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use.
• Colorectal cancer. It is unclear if oral glucosamine reduces the risk of colorectal cancer. Details: A large, observational study in adults has found that regular use of oral glucosamine is not associated with a reduced risk of colorectal cancer over a median of 7 years of follow-up, regardless of sex, age, body mass index, smoking status, or non-steroidal anti-inflammatory drug use (108018). This study did not clarify the form or dose of glucosamine used or the frequency or duration of use.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral glucosamine is beneficial for COVID-19. Details: A large observational study in adults suggests that regular glucosamine use over a median of 1.7 years is not linked to a lower odds of COVID-19 infection but is associated with a 20% lower risk of hospital admission and a 19% lower risk of mortality due to COVID-19 when compared with adults not using glucosamine (111649). This study did not clarify the form or dose of glucosamine used or the frequency or duration of use.
• Dementia. Observational studies suggest that long-term, regular glucosamine intake might reduce the risk of developing certain types of dementia. Details: An observational study has found that regularly taking glucosamine for an average of 8.9 years is associated with a 19% lower risk of developing dementia, including Alzheimer disease and vascular dementia (110630). Another large observational study in older adults without dementia suggests that regularly taking glucosamine for a median of 12 years is associated with an 18% lower risk of vascular dementia. However, habitual glucosamine consumption is not associated with a reduced risk of Alzheimer disease or frontotemporal dementia (112461).
• Depression. It is unclear if oral glucosamine hydrochloride reduces depression symptoms. Details: A small, open-label clinical trial in patients with unipolar depression shows that taking glucosamine hydrochloride 1 gram daily for 1 week, followed by 2 grams daily for 3 weeks, reduces scores on the Hamilton Rating Scale for Depression (HAM-D) and Montgomery-Asberg Depression Rating Scale (MADRS) by 31% or 33% when compared to baseline. However, only 20% of patients experienced a 50% or greater reduction in HAM-D scores, and there were no improvements in Clinical Global Impression scores (103281). The lack of a control group limits the validity of these findings.
• Diabetes. It is unclear if oral glucosamine reduces the risk of developing type 2 diabetes in adults. Details: Observational research in adults in the United Kingdom has found that glucosamine use is associated with a 17% lower risk of type 2 diabetes. The relationship between glucosamine use and diabetes appears to be even more pronounced in patients with high baseline levels of C-reactive protein, a marker of inflammation (103234). However, this study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine use also reported overall healthier lifestyle habits than those that were not taking glucosamine. Although this study attempted to control for these differences, higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and the risk for diabetes.
• Gout. It is unclear if oral glucosamine reduces the risk of developing gout. Details: Observational research in adults in the United Kingdom has found that glucosamine use is associated with a 19% lower risk of gout in females, but not males (109644). However, this study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine use also reported overall healthier lifestyle habits than those that were not taking glucosamine. Although this study attempted to control for these differences, higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and the risk for gout.
• Heart failure. It is unclear if oral glucosamine prevents heart failure. Details: A large, prospective observational study in adults without heart failure suggests that taking glucosamine regularly over a median of 9 years is associated with a 13% lower risk of developing heart failure when compared with adults not taking glucosamine (111646). This study did not clarify the form or dose of glucosamine used or the frequency or duration of use.
• Hyperlipidemia. It is unclear if oral glucosamine hydrochloride improves hyperlipidemia when used with conventional medicine. Details: Preliminary clinical research shows that glucosamine hydrochloride does not reduce cholesterol or triglyceride levels in patients with hyperlipidemia. A small crossover study in older adults taking simvastatin or atorvastatin shows that adding a specific glucosamine hydrochloride product (Artrox, Pfizer) 750 mg twice daily for 4 weeks does not seem to affect lipid levels when compared with placebo (18341).
• Inflammatory bowel disease (IBD). It is unclear if oral or rectal N-acetyl glucosamine improves symptoms of IBD in children. Details: A very small clinical study in children ages 8-17 years with Crohn disease or ulcerative colitis that were unresponsive to conventional treatment suggests that oral or rectal N-acetyl glucosamine 1.5-2 grams in 10 mL water twice daily for 6 weeks might decrease symptoms of IBD when compared with baseline (10234). The validity of this finding is limited by a lack of control group.
• Interstitial cystitis. Oral glucosamine sulfate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: An open-label clinical study in patients with interstitial cystitis shows that taking a specific product (CystoProtek, Tischon Corporation) containing glucosamine sulfate 120 mg, sodium hyaluronate 10 mg, chondroitin sulfate 150 mg, quercetin 150 mg, and rutin 20 mg per capsule, as two capsules twice daily for 12 months, reduces symptom severity by up to 52% when compared with baseline (42391). The validity of this finding is limited by a lack of control group.
• Joint pain. Oral glucosamine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with joint pain shows that taking capsules of a specific combination product (Instaflex Joint Support, Direct Digital) containing glucosamine sulfate 1500 mg, methylsulfonylmethane 500 mg, white willow bark extract 250 mg, ginger root concentrate 50 mg, Boswellia serrata extract 125 mg, turmeric root extract 50 mg, cayenne 40 m H.U. 50 mg, and hyaluronic acid 4 mg, daily in three divided doses for 8 weeks, reduces joint pain severity by 37% compared to only 16% with placebo. However, the specific combination product does not appear to improve joint stiffness or function compared with placebo (89560).
• Kashin-Beck Disease. It is unclear if oral glucosamine hydrochloride improves Kashin-Beck Disease symptoms such as pain. Details: A small clinical study in Chinese adults with Kashin-Beck Disease shows that taking glucosamine hydrochloride 480 mg three times daily along with chondroitin sulfate 600 mg twice daily for 6 months decreases pain scores by at least 20% to 50% in more patients when compared with placebo. Taking glucosamine alone had a non-significant trend toward pain reduction in these patients (42516). An open-label study in Chinese adults with Kashin-Beck Disease shows that taking glucosamine hydrochloride 750 mg twice daily for 6 weeks seems to be no different for improving pain and physical function when compared with taking to diclofenac 50 mg twice daily or naproxen 300 mg twice daily (18339). The validity of this finding is limited by a lack of blinding.
• Kidney stones (nephrolithiasis). Oral glucosamine might reduce the risk of developing kidney stones. Details: A large observational study in adults without kidney stones suggests that regularly taking glucosamine is associated with a 28% lower risk of new-onset kidney stones in people with a total sedentary time under 3.5 hours daily. This association follows a dose-dependent relationship. However, regular glucosamine use does not seem to reduce the risk of new-onset kidney stones in people with total sedentary time exceeding 3.5 hours daily (112451).
• Knee pain. Small clinical studies suggest that oral glucosamine hydrochloride might improve exercise-induced knee pain and chronic knee pain. However, it is unclear if glucosamine sulfate, N-acetyl glucosamine, or lower doses of glucosamine hydrochloride are beneficial in these patients. Details: A small clinical study in athletes following an acute knee injury shows that taking glucosamine sulfate 500 mg three times daily for 28 days does not improve pain but might modestly improve mobility when compared with placebo (20103). Glucosamine has also been evaluated for chronic knee pain. A small clinical study in patients with chronic knee pain of unclear origin shows that taking glucosamine hydrochloride 2000 mg daily for 12 weeks might modestly improve pain when compared with placebo (10312). However, lower doses of glucosamine hydrochloride and N-acetyl glucosamine used in combination with other ingredients have not demonstrated benefit for chronic knee pain. A small clinical trial in Japanese adults over 40 with knee pain shows that taking a combination supplement with glucosamine hydrochloride and other ingredients for 16 weeks does not improve pain, function, or walking speed when compared with placebo. The combination supplement provided glucosamine hydrochloride 1200 mg, chondroitin sulfate 60 mg, type II collagen peptides 45 mg, quercetin glycosides 90 mg, imidazole peptides 10 mg, and vitamin D 200 IU daily (95784). Another small clinical study in Japanese patients over 50 years of age with chronic knee pain shows that taking a specific supplement (Walker's Glucosamine, Kyowa) containing N-acetyl glucosamine 100 mg and chondroitin sulfate 180 mg daily for 24 weeks does not reduce pain or improve knee function when compared with placebo (95795).
• Multiple sclerosis (MS). It is unclear if oral glucosamine sulfate is beneficial in patients with MS. Details: A small clinical study in patients with MS shows that taking glucosamine sulfate 1000 mg once daily for 6 months modestly reduces relapse when compared to baseline, but not when compared with placebo (20104).
• Overall mortality. It is unclear if oral glucosamine reduces overall mortality. Details: An observational study in the United States has found that regular use of oral glucosamine, with or without chondroitin, for an average of 8 years is associated with a 30% lower risk of mortality when compared with no glucosamine use. However, when adjusted for covariates such as age, body-mass index, and comorbidities, there was no difference in overall mortality (110626). In contrast, a cross-sectional observational study has found that using oral glucosamine and chondroitin for at least one year is associated with 27% reduced incidence of overall mortality and 58% reduced incidence of cardiovascular mortality when compared with not using these supplements (104445). This study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine and chondroitin use also reported overall healthier lifestyle habits than those that were not taking glucosamine and chondroitin. Although this study attempted to control for these differences, higher quality, prospective research is needed to clarify the relationship, if any, with overall mortality. Of note, some researchers have called into question the results from observational research linking glucosamine use to a lower rate of overall mortality, claiming that these studies suffer from a high risk of selection bias (109646).
• Postoperative recovery. It is unclear if oral glucosamine sulfate improves recovery after surgery. Details: A small clinical study in male athletes who have undergone anterior cruciate ligament (ACL) reconstruction shows that taking glucosamine sulfate (Solgar Inc.) 1000 mg daily for 8 weeks does not improve rehabilitation outcomes such as functional ability, pain, and muscular performance when compared with placebo (95584).
• Rheumatoid arthritis (RA). It is unclear if oral glucosamine hydrochloride is beneficial in patients with RA. Details: A small clinical study in patients with RA shows that taking glucosamine hydrochloride tablets (Rohto Pharmaceutical Co.) 500 mg three times daily by mouth for 12 weeks reduces pain, but not the number of painful or swollen joints, when compared with placebo (17407).
• Stroke. It is unclear if oral glucosamine is beneficial for reducing stroke risk. Details: An observational cohort study of adults in the United Kingdom found that taking glucosamine is associated with a modest 9% reduced risk for overall stroke; however, sub-analyses show that glucosamine use is not associated with a reduced risk for fatal or non-fatal stroke, hemorrhagic stroke, or ischemic stroke (99682). This study did not clarify the form of glucosamine used, or the dose, frequency, or duration of use. Furthermore, the adults that reported glucosamine use also reported overall healthier lifestyle habits than those that were not taking glucosamine. A case-control study in Spanish patients found that glucosamine use is associated with 45% lower odds of ischemic stroke when compared with non-use; however, the benefit was only observed in patients taking glucosamine for 1 year or less (109643). This study did not clarify the form of glucosamine used or the dose or frequency of use. Furthermore, patients in the control group were generally healthier and less likely to have a history of cardiovascular disease, diabetes, or hyperlipidemia. Although both studies attempted to control for differences between patient populations, higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and stroke risk.
• Temporomandibular disorders (TMD). It is unclear if oral glucosamine sulfate is beneficial in patients with temporomandibular joint osteoarthritis. Details: A small and low-quality clinical study in patients with temporomandibular joint osteoarthritis shows that taking glucosamine sulfate 500 mg three times daily for 90 days seems to be no different than taking ibuprofen 400 mg three times daily for relieving pain and improving functional abilities such as chewing, yawning, talking, and laughing (3714). However, another small clinical study in patients with the same condition shows that taking glucosamine sulfate 1200 mg daily for 6 weeks does not improve pain or jaw opening capacity when compared with placebo (20105). Glucosamine sulfate has also been evaluated in combination with chondroitin for this condition. A meta-analysis of two small clinical studies in patients with TMD shows that taking glucosamine sulfate 1500 mg and chondroitin sulfate 1200 mg daily for 2 months does not reduce pain or increase maximum mouth opening when compared with tramadol 50-100 mg daily (109647). Another small clinical trial in children aged 10-13 years with class II malocclusion shows that application of a specific combination gel product containing glucosamine, chondroitin, and essential oils (Jointace Gel, Vitabiotics) with an expander device, twice daily for 3 months does not improve temporomandibular space measures or pain or tension scores, when compared with placebo (110629).
• Wound healing. Although there is interest in using topical glucosamine for wound healing, there is insufficient reliable information about the clinical effects of glucosamine for this condition. More evidence is needed to rate glucosamine for these uses.

(Read more about GLUCOSAMINE)

POSSIBLY EFFECTIVE

• Osteoarthritis. Most clinical research shows that MSM is modestly beneficial when used alone or in combination with other ingredients. Details: Clinical research shows that taking MSM 1.5-6 grams orally in two to three divided doses daily, either alone or in combination with glucosamine, can modestly improve joint function and some symptoms of osteoarthritis such as pain and swelling (12469,14335,17127,19312). However, MSM does not seem to reduce stiffness or total symptom score (14335). Also, some patients may not consider the modest benefit to be clinically significant (17127). Some clinical research has evaluated MSM in combination with other ingredients. One clinical study in adults with knee osteoarthritis shows that taking MSM 500 mg, glucosamine sulfate 1500 mg, and chondroitin sulfate 1200 mg daily for 12 weeks is associated with greater reductions in pain and osteoarthritis scores when compared with glucosamine sulfate and chondroitin sulfate alone (96447). Clinical studies using combination products containing MSM 5 grams daily and boswellic acid 7.2 mg daily with or without vitamin C (Lignisul, Triterpenol; Artosulfur C, Laborest Italia S.p.A), orally for 60 days show reductions in anti-inflammatory drug use, but conflicting results for pain reduction (19313,96446). Also, one small study suggests that taking a combination of MSM with collagen type II, cetyl myristoleate, lipase, vitamin C, turmeric, and bromelain (AR7 Joint Complex, Robinson Pharma) orally for 12 weeks improves scores for joint pain and tenderness, but does not improve X-rays of affected joints (19314).

POSSIBLY INEFFECTIVE

• Chronic venous insufficiency (CVI). Clinical research suggests that topical MSM is not beneficial in CVI. Details: Clinical research shows that topical application of MSM plus EDTA can reduce the circumference of the calf, ankle, and foot in patients with CVI. However, application of MSM alone appears to increase swelling in these patients (19315).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. It is unclear if oral MSM improves the appearance of aging skin to a clinically meaningful extent. Details: Preliminary clinical research shows that taking MSM (OptiMSM, Bergstrom Nutrition) 3 grams daily for 16 weeks improves facial wrinkles associated with aging by a moderate amount when compared with placebo. When compared with baseline, taking MSM 1 gram daily for 16 weeks is as effective as taking 3 grams for reducing fine lines and wrinkles and improving smoothness, radiance, firmness, and elasticity (102000).
• Allergic rhinitis (hay fever). It is unclear if oral MSM is beneficial in patients with allergic rhinitis. Details: Preliminary clinical research shows that taking MSM (OptiMSM 650 mg) 2600 mg orally for 30 days might relieve some symptoms of seasonal allergic rhinitis when compared with baseline (8574). However, this study lacked blinding and a control group, and also did not provide information on severity of symptoms (12000).
• Alzheimer disease. Although there is interest in using oral MSM for Alzheimer disease, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Androgenic alopecia. Although there is interest in using oral and topical MSM for androgenic alopecia, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Aromatase inhibitor-induced arthralgia. Oral MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with estrogen receptor positive (ER+) breast cancer and aromatase inhibitor-induced arthralgia shows that taking a specific combination product (Opera, GAMFARMA s.r.l) containing MSM 200 mg, boswellia 40 mg, alpha-lipoic acid 240 mg, and bromelain 20 mg once daily for 6 months reduces arthralgia intensity when compared to baseline, with around 22% of patients having complete symptom resolution at the end of the study (109570). The validity of these findings is limited by a lack of control group.
• Asthma. Although there is interest in using oral MSM for asthma, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Athletic performance. It is unclear if topical MSM is beneficial for improving athletic performance. Details: A small clinical study in healthy, physically active adults shows that applying a specific cream containing magnesium and MSM (MagPro, Custom Prescription Shoppe) prior to stretching and pedaling on a stationary bicycle does not appear to improve flexibility or endurance when compared with a placebo cream (19317).
• Chemotherapy-induced peripheral neuropathy. Oral MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with chemotherapy-induced peripheral neuropathy shows that taking a specific product (OPERA, GAMFARMA s.r.l.) containing MSM 200 mg, alpha-lipoic acid 240 mg, boswellia 40 mg, and bromelain 20 mg daily for 12 weeks reduces overall pain when compared with baseline (96449). The validity of these findings is limited by the lack of a placebo group. Additionally, it is not clear if benefit is associated with MSM, other ingredients, or the combination.
• Chronic fatigue syndrome (CFS). Although there is interest in using oral MSM for CFS, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Chronic obstructive pulmonary disease (COPD). Although there is interest in using oral MSM for COPD, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Constipation. Although there is interest in using oral MSM for constipation, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Diabetes. Although there is interest in using oral MSM for diabetes, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Dyslipidemia. It is unclear if oral MSM is beneficial for dyslipidemia. Details: A very small clinical study in adults with overweight or obesity shows that taking a specific MSM product (OptiMSM, Bergstrom Nutrition) 3 grams daily for 16 weeks modestly increases high-density lipoprotein (HDL) cholesterol when compared with baseline, but not when compared with placebo. Taking MSM also did not improve total cholesterol, low-density lipoprotein (LDL) cholesterol, very-low-density lipoprotein (VLDL) cholesterol, or triglycerides (110572). However, this study may have been underpowered to detect differences between groups.
• Dyspepsia. Although there is interest in using oral MSM for dyspepsia, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Exercise-induced muscle damage. It is unclear if oral MSM is beneficial for preventing exercise-induced muscle damage. Details: Clinical research shows that taking MSM 50 mg/kg in 200 mL water orally daily beginning 10 days prior to a 14-km run can attenuate the increase in creatine kinase (CK) and bilirubin levels caused by exercise-induced muscle damage (19320). However, other clinical research shows that taking MSM (OptiMSM, Bergstrom Nutrition) 3 grams daily beginning 3 weeks prior to a 13.1-mile run and continuing for 2 days after does not reduce muscle or joint pain or alter serum markers of oxidative stress or muscle damage when compared with placebo (96448).
• Hangover. Although there is interest in using oral MSM for hangover, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Hemorrhoids. Topical MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that applying a specific gel containing MSM in combination with hyaluronic acid and tea tree oil (Proctoial, BSD Pharma) for 14 days improves symptoms of hemorrhoids, including pain during defecation, visible bleeding, and inflammation/irritation, when compared with placebo (19318). It is not clear if these effects are due to MSM, the other ingredients, or the combination.
• Insect bite. Although there is interest in using oral MSM for preventing insect bites, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Interstitial cystitis. Although there is interest in using oral MSM for interstitial cystitis, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Muscle cramps. Although there is interest in using oral MSM for muscle cramps, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Obesity. It is unclear if oral MSM is beneficial for obesity. Details: A very small clinical study in adults with overweight or obesity shows that taking a specific MSM product (OptiMSM, Bergstrom Nutrition) 3 grams daily for 16 weeks does not improve body weight, body mass index, waist circumference, or body composition when compared with placebo. (110572). However, this study may have been underpowered to detect differences between groups.
• Osteoporosis. Although there is interest in using oral MSM for osteoporosis, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Periodontitis. Although there is interest in using topical MSM for periodontitis, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Pneumonia. Although there is interest in using oral MSM for pneumonia, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Postoperative pain. Oral MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients who have undergone arthroscopic rotator cuff repair shows that taking a specific combination product (Tenosan, Agave s.r.l.) containing MSM 550 mg, arginine alpha-ketoglutarate 500 mg, collagen peptides 300 mg, apple and grape polyphenols 125 mg, bromelain 40 mg, and vitamin C 60 mg for 3 months can reduce postoperative pain and slightly improve repair integrity (19322). However, improvement in overall functional outcomes was not observed.
• Rheumatoid arthritis (RA). Although there is interest in using oral and topical MSM for RA, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Rosacea. Oral MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with rosacea shows that topical application of a cream containing silymarin and MSM twice daily for one month improves skin redness, papules, itching, hydration, and skin color when compared to baseline (19319). The validity of these findings is limited by the lack of a comparator group.
• Scleroderma. Although there is interest in using oral and topical MSM for scleroderma, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Stretch marks (striae gravidarum). Although there is interest in using topical MSM for stretch marks, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Systemic lupus erythematosus (SLE). Although there is interest in using oral MSM for SLE, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Temporomandibular disorders (TMD). Although there is interest in using oral MSM for TMD, there is insufficient reliable information about the clinical effects of MSM for this condition.
• Tendinopathy. Oral MSM has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with Achilles tendinopathy shows that taking two sachets orally daily of a specific combination product (Tenosan, Agave s.r.l.) each containing MSM 550 mg, arginine alpha-ketoglutarate 500 mg, collagen peptides 300 mg, apple and grape polyphenols (Vinitrox) 125 mg, bromelain 50 mg, and vitamin C 60 mg for 60 days might improve the outcomes of extracorporeal shock wave therapy (ESWT) (19321). However, it is unclear if any benefit is due to MSM, other ingredients, or the combination.
• Wound healing. Although there is interest in using topical MSM for wound healing, there is insufficient reliable information about the clinical effects of MSM for this condition. More evidence is needed to rate MSM for these uses.

(Read more about METHYLSULFONYLMETHANE (MSM))

LIKELY SAFE ...when used orally and appropriately. Boswellia serrata extract in doses up to 1000 mg daily has been safely used in several clinical trials lasting up to 6 months (1708,1709,12432,12434,12438,17948,17949,17950,91379)(100699,100713,102089,109568). Boswellia serrata extract has been used with apparent safety at a dose of 2400 mg for up to 1 month (102092).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (4912). There is insufficient reliable information available about the safety of using Boswellia serrata in medicinal amounts; avoid using.

(Read more about BOSWELLIA SERRATA)

LIKELY SAFE ...when used orally and appropriately. Chondroitin sulfate has been used safely in doses of up to 2000 mg daily for up to 6 years (1955,2533,13579,17732,22212,42339,42343,42348,42389,42396)(42398,42463,42477,42513,42520,42536,42541,89516,89558,89592)(89596,94360,94381,95788,95792). However, since chondroitin is often derived from bovine cartilage, historically, there was concern about contamination with diseased animal parts (1825). So far, there are no reports of disease transmission to humans due to use of contaminated chondroitin preparations. ...when used topically and appropriately as an ophthalmic viscosurgical device (OVD). Various products containing chondroitin sulfate and sodium hyaluronate have been granted approval by the US Food and Drug Administration (FDA) for use as an adjunct to cataract surgery (89436,89437).

POSSIBLY SAFE ...when used intramuscularly (10149,42397). ...when used topically as eye drops, short-term. Eye drops containing chondroitin sulfate with xanthan gum or glucosamine have been used with apparent safety four times daily for up to 3 months (89591,104443). ...when administered intravesically under the supervision of a physician (42338,42371,42373,42385,42387,42473,42511,42517,42519,109649).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about CHONDROITIN SULFATE)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Collagen peptides have been used with apparent safety at doses up to 10 grams daily for up to 6 months and in doses up to 40 grams daily for up to 4 weeks (97632,97635,101615,101621,104638,104643,104644,104647,101622,110667). PREGNANCY &

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about COLLAGEN PEPTIDES)

LIKELY SAFE ...when glucosamine sulfate is used orally and appropriately. Glucosamine sulfate has been used safely in multiple clinical trials at a dose of 1000-1500 mg daily for 4 weeks to 3 years (2604,7026,8942,11340,12461)(14305,16717,89558,89567,94380,94382,95785).

POSSIBLY SAFE ...when glucosamine hydrochloride is used orally and appropriately. Glucosamine hydrochloride has been used with apparent safety at a dose of 1400-1600 mg daily for up to 2 years (4237,13579,14809,18344,42477,89516,89519,95784). Glucosamine hydrochloride 2 grams daily has also been used with apparent safety for up to 3 weeks (103281). ...when N-acetyl glucosamine is used orally and appropriately. N-acetyl glucosamine 100 mg daily has been used with apparent safety for up to 24 weeks (95795). ...when N-acetyl glucosamine is applied topically and appropriately. A 2% N-acetyl glucosamine cream has been safely used for up to 10 weeks (92721). ...when N-acetyl glucosamine is used rectally and appropriately. N-acetyl glucosamine 3-4 grams daily in 2 divided doses has been safely used (10234). ...when glucosamine sulfate is used intramuscularly and appropriately, short-term. Intramuscular glucosamine sulfate seems to be well tolerated when given twice weekly for up to 6 weeks (2605).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about GLUCOSAMINE)

POSSIBLY SAFE ...when used orally and appropriately, short term. MSM in doses of 1.5-6 grams daily or 50 mg/kg daily has been used safely in studies lasting up to 6 months (8574,12469,14335,17127,19312,96446,96448,102555). One specific product (OptiMSM, Bergstrom Nutrition) is Generally Recognized As Safe (GRAS) by the United States Food and Drug Administration (FDA) (102555). ...when used topically. Topical cream containing MSM and silymarin, as well as topical gel containing MSM, hyaluronic acid, and tea tree oil, have been used with apparent safety for up to 20 days (19318,19319).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about METHYLSULFONYLMETHANE (MSM))

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might increase the levels of CYP1A2 substrates.  Details In vitro research shows that Boswellia serrata gum resin inhibits CYP1A2 enzymes (21178).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might increase the levels of CYP2C19 substrates.  Details In vitro research shows that Boswellia serrata gum resin inhibits CYP2C19 enzymes (21178).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might increase the levels of CYP2C9 substrates.  Details In vitro research shows that Boswellia serrata gum resin inhibits CYP2C9 enzymes (21178).

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might increase the levels of CYP2D6 substrates.  Details In vitro research shows that Boswellia serrata gum resin inhibits CYP2D6 enzymes (21178).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might increase the levels of CYP3A4 substrates.  Details In vitro research shows that Boswellia serrata gum resin inhibits CYP3A4 enzymes (21178).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, Boswellia serrata might alter the effects of immunosuppressive drugs.  Details Some in vitro research suggests that Boswellia serrata extracts might inhibit mediators of autoimmune disorders such as leukotrienes and reduce production of antibodies and cell-mediated immunity (12432,12435,12437,12438). However, other in vitro research suggests that, when coupled with calcium ions, boswellic acids containing the keto group have immunostimulant properties within specific cell signaling pathways (21180).

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WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Unlikely •  Level of Evidence = D Taking chondroitin in combination with glucosamine might increase the anticoagulant effects of warfarin. However, the effect of chondroitin alone is unclear.  Details There have been multiple reports of increased international normalized ratio (INR) in patients taking warfarin with glucosamine, with or without chondroitin. The lack of reports with chondroitin alone seem to suggest that the interactions occurring in these reports may have been due to glucosamine. In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in INR in patients previously stabilized on warfarin (11389,16130). Additionally, 20 voluntary case reports to the US Food & Drug Administration (FDA) have linked glucosamine plus chondroitin with increased INR, bruising, and bleeding in patients who were also taking warfarin (16130). There have also been 20 additional case reports to the World Health Organization (WHO) that link glucosamine alone, without chondroitin, to increased INR in patients taking warfarin (16131).

(Read more about CHONDROITIN SULFATE)

(Read more about COLLAGEN PEPTIDES)

ACETAMINOPHEN (Tylenol, others) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Acetaminophen might interfere with the activity of glucosamine sulfate by interacting with the sulfate portion.  Details Anecdotal reports suggest that adding glucosamine to an acetaminophen regimen might decrease pain control in patients with osteoarthritis (14806). Some research suggests that the sulfate portion of glucosamine sulfate might contribute to its effect in osteoarthritis. Since acetaminophen metabolism requires sulfur and reduces serum sulfate concentrations, acetaminophen could theoretically interfere with the action of glucosamine sulfate. Conversely, the administration of sulfate could theoretically decrease the effectiveness of acetaminophen in sulfate-deficient people by increasing its clearance (10313).

ANTIDIABETES DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Despite initial concerns, it is unlikely that glucosamine will interfere with the effects of antidiabetes drugs.  Details In vitro and animal research has suggested that glucosamine might increase insulin resistance or decrease insulin production (371,372,3406,18342,18343). This has raised concerns that taking glucosamine might worsen diabetes and decrease the effectiveness of diabetes drugs. However, clinical research suggests that glucosamine does not have adverse effects on blood glucose or glycated hemoglobin (HbA1C) in healthy, obese, or type 2 diabetes patients (7026,7075,8942,10311,10317,15111).

TOPOISOMERASE II INHIBITORS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically glucosamine may induce resistance to topoisomerase II inhibitors.  Details In vitro research suggests that glucosamine might induce resistance to etoposide (VP16, VePesid) and doxorubicin (Adriamycin) by reducing inhibition of topoisomerase II, an enzyme required for DNA replication in tumor cells (7639). This effect has not been reported in humans.

WARFARIN (Coumadin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = D Glucosamine might increase the anticoagulant effects of warfarin and increase the risk of bruising and bleeding.  Details In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in international normalized ratio (INR) in patients previously stabilized on warfarin (11389,16130). In one case, the increase in INR occurred only after tripling the dose of a glucosamine/chondroitin supplement from 500 mg/400 mg daily to 1500/1200 mg daily (16130). Additionally, 20 voluntary case reports to the U.S. Food & Drug Administration (FDA) have linked glucosamine plus chondroitin with increased INR, bruising, and bleeding in patients who were also taking warfarin (16130). There have also been 20 additional case reports to the World Health Organization (WHO) that link glucosamine alone to increased INR in patients taking warfarin (16131). The mechanism of this interaction is unclear. Glucosamine is a small component of heparin, but is not thought to have anticoagulant activity; however, animal research suggests that it might have antiplatelet activity (16131).

(Read more about GLUCOSAMINE)

(Read more about METHYLSULFONYLMETHANE (MSM))

General ...Orally, Boswellia serrata extract is generally well-tolerated. For information on the safety of Boswellia serrata when applied topically or used as aromatherapy, see the Frankincense monograph.
Most Common Adverse Effects:
Orally: Abdominal pain, diarrhea, headache, heartburn, itching, nausea.
Serious Adverse Effects (Rare):
Orally: Large amounts of Boswellia serrata gum resin can cause bezoar formation.

Dermatologic ...Orally, Boswellia serrata extract (5-Loxin) has been associated with itching at doses of 100-250 mg daily (17948).

Gastrointestinal ...Orally, Boswellia serrata extract may cause diarrhea, nausea, abdominal pain, and heartburn (1708,12432,12438,17948,17949,17950,21149,109567). A case of a large gastrointestinal bezoar has been reported in a 17-year-old female who chewed and swallowed large quantities of boswellia gum resin (Boswellia species not specified) for celiac disease (36914).

Musculoskeletal ...Orally, Boswellia serrata extract (5-Loxin) has been associated with one case of foot edema and four cases of generalized weakness in one clinical study (17948).

Neurologic/CNS ...Orally, Boswellia serrata extract may cause dizziness, headache, and vertigo. In one clinical study, nearly 11% of patients taking a specific Boswellia serrata extract (K-Vie) reported headache. Dizziness and vertigo were also reported, but at lower rates (109567). In another study, headache was reported in one patient taking a specific Boswellia serrata extract (5-Loxin) (17948).

Psychiatric ...Orally, one case of mania is reported in a 73-year-old male who took Boswellia powder mixed with honey for 3 days. The patient recovered after hospitalization and treatment with olanzapine (110526).

(Read more about BOSWELLIA SERRATA)

General ...Orally and topically, chondroitin sulfate is generally well tolerated. Intramuscular and ophthalmic use also seems to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, bloating, constipation, diarrhea, heartburn, nausea.
Serious Adverse Effects (Rare):
Orally: There have been rare reports of hepatotoxicity.

Cardiovascular ...One case of congestive heart failure and another case of myocardial infarction has been possibly attributed to use of glucosamine hydrochloride and chondroitin sulfate (13579,42477). Also, a case of mesenteric occlusion in one patient was considered possibly related to treatment with chondroitin sulfate and glucosamine (89520).

Dermatologic ...Orally, chondroitin sulfate has been associated with skin symptoms, such as eyelid edema, lower limb edema, alopecia, and skin rash (42513). Combinations of chondroitin sulfate along with glucosamine hydrochloride may also be associated with rash, water retention around eyes and scars, and hives on face, chest, torso, and legs when taken orally (42436,110628). A case of photosensitization that was reproducible with rechallenge has been reported following treatment with oral glucosamine-chondroitin products. However, it is not clear if this effect was due to glucosamine, chondroitin sulfate, or contaminants in the product (10408). A case of rash following treatment with intravesical chondroitin sulfate has been reported to be possibly related to the product (42385).

Gastrointestinal ...Orally, chondroitin might cause nausea, bloating, abdominal pain, diarrhea, constipation, vomiting, dyspepsia, and epigastric burning (42396,42436,42541,89561,110628,111647).

Genitourinary ...Intravesical chondroitin sulfate has been associated with cases of vulvar burning, vaginitis, urinary tract infection (UTI), dysuria, pelvic pain, and other bladder symptoms, such as increased frequency, urgency, or incontinence. However, these effects might be due to catheterization rather than chondroitin sulfate (42385,42387,42473).

Hematologic ...Concern has been expressed about possible anticoagulant activity of oral chondroitin sulfate. However, hematological changes have not occurred in patients taking chondroitin sulfate in clinical trials (760).

Hepatic ...Although relatively uncommon, combinations of glucosamine and chondroitin sulfate have been associated with acute liver injury that mimics autoimmune hepatitis. Two cases of elevated aminotransferase levels have been reported for patients taking glucosamine (form unspecified) and chondroitin sulfate at recommended doses. Aminotransferase levels, which were increased by four- to seven-fold, returned to normal following discontinuation of treatment (89515). Another case of abdominal pain, jaundice, fatigue, and elevated liver enzymes has been reported for a patient who used chondroitin sulfate (Condrosulf) for 2 years followed by a combination of glucosamine sulfate and chondroitin sulfate (Vita Mobility Complex) for 8 weeks. The patient required maintenance treatment with azathioprine to remain in remission (89518). A case of acute cholestatic hepatitis due to Glucosamine Forte, which contains glucosamine hydrochloride, chondroitin sulfate, Devil's claw, and shark cartilage, has been reported (89522). It is unclear whether these adverse events were related to chondroitin sulfate, other ingredients, or the combination.

Musculoskeletal ...Orally, chondroitin has been associated with musculoskeletal and connective-tissue events and disorders (13579,42520,95516).

Neurologic/CNS ...Rare cases of headache have been reported following treatment with products containing a combination of oral chondroitin sulfate and glucosamine hydrochloride or glucosamine sulfate (42436,89561). It is unclear if this effect was due to chondroitin, glucosamine, or the combination.
Patients should adhere to product directions when using chondroitin sulfate products that contain manganese. When taken at doses slightly higher than the recommended dose, these products can sometimes supply greater than the tolerable upper limit (UL) for manganese of 11 mg per day. Ingestion of more than 11 mg per day of manganese might cause significant central nervous system toxicity (7135).

Ocular/Otic ...A case of bilateral pinna chondritis (inflammation of the cartilage of the external ear) has been reported for a patient who received supplements containing glucosamine and chondroitin sulfate (42503).

Pulmonary/Respiratory ...A case of asthma exacerbation has been reported occurred following use of an oral glucosamine and chondroitin sulfate combination product (10002).

(Read more about CHONDROITIN SULFATE)

General ...Orally, collagen peptides seem to be well tolerated.

Dermatologic ...Orally, a case of a mild skin rash has been reported for a patient who used a specific collagen peptide-containing product (BioCell Collagen) (28680).

Gastrointestinal ...Orally, collagen peptides may cause nausea, dyspepsia, diarrhea, and flatulence, but these adverse effects are rare (101622,104639).

(Read more about COLLAGEN PEPTIDES)

General ...Orally, all forms of glucosamine seem to be well tolerated. Topically and rectally, N-acetyl glucosamine also seems to be well tolerated. Intramuscularly, glucosamine sulfate seems to be well tolerated. However, a thorough evaluation of safety outcomes has not been conducted for non-oral routes of administration.
Most Common Adverse Effects:
Orally: Bloating, constipation, cramps, diarrhea, heartburn, nausea.
Serious Adverse Effects (Rare):
Orally: There have been rare reports of severe allergic reactions and hepatotoxicity.

Cardiovascular ...One case of mesenteric occlusion in a clinical trial was considered possibly related to use of oral glucosamine hydrochloride and chondroitin sulfate (89520).
Some observational research has found that glucosamine use in patients with osteoarthritis is associated with a higher risk of cardiovascular disease (CVD) events when compared with non-use (109642). However, glucosamine users tended to be older, have multiple comorbidities, and be on antihyperlipidemic or antiplatelet therapy. Furthermore, other observational research in healthy adults has found that glucosamine use is associated with a reduced risk of fatal and non-fatal CVD events (99682). Higher quality, prospective research is needed to clarify the relationship, if any, between glucosamine and CVD risk.

Dermatologic ...Orally, glucosamine might cause skin reactions, including itching, rash, and erythema (2608,20084,89567,110628). Also, fingernail and toenail toughening, with an increased rate of growth, has been reported (89572). Topically, N-acetyl glucosamine 2% with niacinamide 4% cream might cause rare skin reactions (92721). Photosensitization that was reproducible with re-challenge was reported in a case report of an individual using glucosamine (form unknown) and chondroitin (10408).

Endocrine ...Orally, glucosamine does not seem to impact blood glucose. Preliminary research and anecdotal reports have found that various forms of glucosamine might increase insulin resistance or decrease insulin production, increasing fasting plasma glucose levels (22,371,372,1203,3406,5059,7637,14810). This has raised concerns that taking glucosamine sulfate might worsen diabetes and decrease the effectiveness of diabetes drugs. However, clinical research suggests that various forms of glucosamine do not have adverse effects on blood glucose or glycated hemoglobin (HbA1C) in healthy, obese, patients with type 2 diabetes or impaired glucose tolerance (7026,7075,7638,8942,10311,10317,12107,14808,15111,89563).

Gastrointestinal ...Orally, glucosamine has been associated with gastrointestinal problems, including epigastric and abdominal pain, cramps, heartburn, diarrhea, nausea, dyspepsia, vomiting, constipation, and flatulence (1520,2608,16717,20084,20104,20105,89561,89562,89567,89568)(108897,110628,111647). In older persons, use of glucosamine sulfate is associated with oral dryness (89564). In a clinical trial, a case of Helicobacter pylori gastritis was considered probably related to the use of glucosamine hydrochloride (89516).

Hepatic ...Although relatively uncommon, combinations of glucosamine and chondroitin sulfate have been associated with acute liver injury that mimics autoimmune hepatitis. Of 151 patients at an outpatient clinic for liver diseases, 23 acknowledged use of products containing glucosamine (form unspecified) and/or chondroitin. However, only 2 cases had an apparent relationship between transaminase elevation and the use of recommended doses of glucosamine and chondroitin sulfate. Aminotransferase levels, which were increased by four- to seven-fold, returned to normal following discontinuation of treatment (89515). In another case, a 65-year-old male presented to the hospital with signs and symptoms of drug-induced autoimmune hepatitis. The patient had used Condrosulf, containing chondroitin sulfate, for two years, followed by Vita Mobility Complex, containing chondroitin sulfate and glucosamine sulfate, for 8 weeks. The patient required maintenance treatment with azathioprine to remain in remission (89518). A case of acute cholestatic hepatitis due to Glucosamine Forte, which contains glucosamine hydrochloride, chondroitin sulfate, Devil's claw, and shark cartilage, has been reported (89522). It is unclear whether these adverse events were related to glucosamine, other ingredients, or the combination.

Immunologic ...There is some concern that glucosamine products might cause allergic reactions in sensitive individuals. One review of glucosamine-related adverse events in Australia found that 72% of all reports involved hypersensitivity reactions. Of these reactions, 35% were mild, including pruritis, urticaria, and lip edema, 49% were moderate, including dyspnea, and 16% were severe, including gait disturbance, somnolence, and hypotension. Anaphylaxis was reported in 1.5% of cases (102115). Also, in one clinical trial, a single patient developed allergic dermatitis considered to be likely due to glucosamine hydrochloride (89516). Glucosamine is derived from the exoskeletons of shrimp, lobster, and crabs. However, it is unclear if these adverse reactions were due to a shellfish sensitivity or general atopy. Additionally, shellfish allergies are caused by IgE antibodies to antigens in the meat of shellfish, not to antigens in the exoskeleton. Regardless, it is possible that some glucosamine products might be contaminated by this allergen during production (102115).

Neurologic/CNS ...Orally, glucosamine has been reported to cause drowsiness and headache (2608,89561). Glucosamine plus chondroitin combination products that also contain manganese (e.g., CosaminDS) should always be taken according to product directions. When taken at doses slightly higher than the recommended dose, these products can sometimes supply greater than the tolerable upper limit (UL) for manganese which is 11 mg/day. Ingestion of more than 11 mg/day of manganese might cause significant central nervous system toxicity (7135).

Ocular/Otic ...In older persons, use of glucosamine sulfate has been associated with ocular dryness (89564). Increased intraocular pressure has occurred with glucosamine sulfate supplementation (89573,112460). Data from the FDA MedWatch adverse event reporting system shows that 0.21% of subjects taking glucosamine reported glaucoma, which is significantly greater than the 0.08% of subjects who reported glaucoma while using any other drug (112460).

Pulmonary/Respiratory ...Cases of asthma exacerbations associated with the use of glucosamine (form unknown)-chondroitin products have been reported (10002).

Renal ...Anecdotal reports have associated glucosamine with nephrotoxicity signals such as modestly elevated creatine phosphokinase and 1+ to 2+ proteinuria, but changes in kidney function have not been reported in long-term studies (7026,8942,10408,10409). It was also noted that effects may have been due to other concurrent medications or impurities in glucosamine-chondroitin products. Cases of acute interstitial nephritis induced by glucosamine (form unknown) have also been reported (89523).

Other ...There has been concern that glucosamine might increase the risk of metabolic disturbances resulting in increased cholesterol levels and blood pressure. However, glucosamine does not appear to increase the risk of these adverse effects. Taking glucosamine sulfate for up to 3 years does not significantly increase blood glucose or lipid levels, or cause any other disturbances in metabolism (7026,7075,8942,10311,10317).

(Read more about GLUCOSAMINE)

General ...Orally, MSM is generally well tolerated.
Most Common Adverse Effects:
Orally: Bloating, diarrhea, gastrointestinal discomfort, nausea.

Dermatologic ...In rare cases, MSM has caused pruritus when taken orally (8574).

Gastrointestinal ...Orally, MSM may cause mild gastrointestinal discomfort, nausea, bloating, and diarrhea (8574,12469).

Immunologic ...Orally, MSM may increase allergy symptoms (8574).

Neurologic/CNS ...Orally, MSM may cause headache, fatigue, insomnia, and difficulty concentrating (8574,14335).

Ocular/Otic ...In a case report, a 35-year-old female presented with bilateral acute angle closure glaucoma, which resolved 4 days after discontinuing a multi-ingredient product. Although the product contained over 35 vitamins, minerals, and other ingredients, only MSM contained sulfur, which the authors suggest acted like a sulfa-drug to cause acute angle closure glaucoma (90613).

(Read more about METHYLSULFONYLMETHANE (MSM))