Phytofed-DF by DC

POSSIBLY EFFECTIVE

• Common cold. Taking echinacea orally while still healthy may help prevent the common cold, but the benefit is probably modest. Echinacea does not seem to have a significant benefit for treating colds that have already developed. Details: Three meta-analyses show a 10% to 58% reduction in the risk of developing a cold when taking various forms of echinacea (17520,17522,95652). A large clinical study shows that adults who use a specific echinacea extract (Echinaforce, A. Vogel Bioforce AG) 0.9 mL three times daily (2400 mg echinacea daily) for 4 months, with an increase to 0.9 mL five times daily (4000 mg echinacea daily) at the first sign of a cold, have 59% fewer cold episodes and 26% fewer days with cold symptoms than those taking placebo (18225). Many smaller studies have shown a non-significant trend toward a prophylactic benefit, but they were likely underpowered to detect a statistically significant difference (3282,6386,17521,95652). Research in adults who are deliberately infected with cold viruses shows that taking echinacea products either does not reduce the incidence of colds, or has a limited effect which is not statistically significant. Products used include E. angustifolia root extract 300 mg three times daily for 7 days before and 5 days after experimental infection (13419), an alcoholic extract of E. purpurea above-ground parts (EchinaGuard, Madaus AG) 2.5 mL three times daily for 7 days before and 7 days after experimental infection (12354), or echinacea 300 mg three times daily for 14 days before and 5 days after experimental infection (8228). These studies are small and have methodological problems. Some small clinical studies have suggested that taking E. purpurea extracts as a tincture or tea to treat the common cold modestly reduces symptom severity and reduces cold duration by a couple of days (6384,10320,10802,12355,14419,20062,111530). Specific products used in these studies include Echinilin by Inovobiologic Inc., and Echinacin and EchinaGuard by Madaus AG (10320,10802,12355,20062). In contrast, higher quality clinical research shows that taking E. purpurea alone or with E. angustifolia does not reduce duration or severity of cold symptoms when compared with placebo (10800,11970,17519,20059). Echinacea has also been evaluated in children. Preliminary clinical research in healthy children 4-12 years old shows that taking a specific E. purpurea product (Echinaforce Junior, A. Vogel) 400 mg three times daily for 4 months reduces the occurrence of cold symptoms, respiratory complications (such as pneumonia and otitis media), and antibiotic prescriptions by 30%, 52%, and 62%, respectively, when compared with vitamin C 50 mg three times daily. Taking echinacea also reduces the average duration of symptoms during respiratory illness by an average of 1.4 days when compared with vitamin C (105719). However, other clinical research in children has found no benefit with a specific E. purpurea product (Echinacin, Madaus AG) (4989,95653).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. It is unclear if oral echinacea reduces anxiety. Details: Preliminary clinical research shows that taking a specific E. angustifolia extract (ExtractumPharma ZRT) 40 mg once or twice daily for 7 days reduces anxiety scores on the State-Trait Anxiety Inventory scale when compared with placebo (20064,103233). This extract seems to be more effective in patients with high baseline anxiety scores (103233). A lower dose of 20 mg daily appears to be ineffective (20064). Conversely, a small clinical study in physically healthy adults with mild to moderate anxiety shows that taking the same E. angustifolia extract at doses of 20 or 40 mg twice daily for 6 weeks does not reduce anxiety when compared with placebo (106626).
• Athletic performance. It is unclear if oral echinacea improves athletic performance in healthy, recreationally active males. Details: Preliminary clinical research in healthy, recreationally active males shows that taking echinacea (Puritan's Pride) 2 grams four times daily for 28 days increases serum erythropoietin levels and maximal oxygen consumption (VO2max) during exercise tests (20066). However, two small clinical studies in endurance trained athletes and in non-athletes with high aerobic fitness show that taking E. purpurea 8 or 16 grams once daily for 35 days in combination with other ingredients (Biomedical Research Lab), or taking E. purpurea (Puritan's Pride) 8 grams daily for 42 days, has no effect on erythropoietin levels, VO2max, or aerobic capacity (95651,101593).
• Atopic dermatitis (eczema). Some evidence shows that an echinacea cream may be effective in mild disease, but it has not been compared to conventional treatments such as corticosteroids. Details: Preliminary clinical research in patients with mild atopic dermatitis shows that applying a cream containing echinacea (Linola Plus Cream, Dr. August Wolff GmbH & Co) 2-3 times daily for 12 weeks reduces symptoms such as erythema, edema, pruritus, and dryness when compared with a cream containing birch bark extract (Imlan Crème Pur, Birken AG). However, the echinacea product was no different to the comparator cream at the 4- and 8-week assessments, indicating that it might take up to 12 weeks to show benefit (97499).
• Attention deficit-hyperactivity disorder (ADHD). Although there has been interest in using oral echinacea for ADHD, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Burns. Although there has been interest in using topical echinacea for burns, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral echinacea for CFS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral echinacea is beneficial for preventing or treating COVID-19. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients.
• Genital herpes. It is unclear if oral echinacea is beneficial for genital herpes in patients with herpes simplex virus (HSV) type 1 or 2. Details: Some clinical research shows that a specific E. purpurea extract (Echinaforce, A. Vogel Bioforce AG) 800 mg orally twice daily for 6 months does not seem to prevent or reduce the frequency or duration of recurrent genital herpes in patients with herpes simplex virus (HSV) type 1 or 2 (7087).
• Gingivitis. Echinacea, in a mouth rinse or periodontal patch, has only been studied in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a mouth rinse containing echinacea, gotu kola, and elderberry (HM-302, Izun Pharmaceuticals) 15 mL three times daily for 14 days might prevent worsening of gingivitis when compared with a placebo rinse, but it produces only minimal improvement in symptoms (20069). Applying a periodontal patch containing echinacea, gotu kola, and elderberry (PerioPatch, Izun Pharmaceuticals) either as a single dose, or three times daily for 1 day then once daily for 2 days seems to reduce some measures of inflammation and gingivitis at some time points, but effects lack consistency (20068,20070).
• Herpes labialis (cold sores). Although there has been interest in using topical echinacea for herpes labialis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• HIV/AIDS. Although there has been interest in using oral echinacea for HIV/AIDS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Human papillomavirus (HPV). Oral echinacea has only been studied in combination with other ingredients; its benefit when used alone is unclear. Details: Preliminary clinical research shows that taking a specific combination product containing echinacea, andrographis, grapefruit, papaya, pau d'arco, and cat's claw (Immune Act, Erba Vita SpA) three tablets daily for one month reduces the recurrence of anal condylomata in patients following surgical removal. After one month, the recurrence rate was about 4% in the echinacea group compared with 18% in the control group; after 6 months the recurrence rates were about 7% and 27%, respectively (20073). However, poor study methodology limits the validity of these findings.
• Influenza. Limited data suggest that oral echinacea may improve the response to influenza vaccine, and that a combination product containing echinacea may improve rates of recovery from influenza. Details: Preliminary clinical research shows that a taking a specific echinacea product (Monoselect Echinacea, PharmExtracta) 200 mg orally daily for 15 days, then 100 mg daily for 15 days, followed by 100 mg every other day for 60 days, might improve the response to influenza vaccine in people with chronic bronchitis or asthma (18226). Higher quality research is needed to confirm these results. Taking a specific combination product (Echinaforce Hot Drink, A. Vogel Bioforce AG), containing elderberry juice and extracts of E. purpurea above-ground parts and roots, 5 mL five times daily for 3 days, then three times daily for 7 days, improves rates of recovery and influenza-related respiratory complications similarly to oseltamivir 75 mg twice daily for 5 days (95650). However, due to the lack of a placebo group, it is unclear if both treatments were beneficial or if the outcomes represent the natural progression of influenza.
• Insect bite. It is unclear if topical homeopathy with a gel containing echinacea is beneficial for insect bite treatment. Oral echinacea has not been evaluated for this use. Details: Preliminary clinical research shows that using a homeopathic after-bite gel, containing echinacea, marsh Labrador tea, and stinging nettle, on affected areas does not reduce erythema or itching after a mosquito bite when compared with placebo (89235).
• Lichen planus. It is unclear if oral echinacea is beneficial for patients with this condition. Details: A small clinical study in adults with erosive oral lichen planus in Iran shows that taking a specific echinacea extract tablet (Immustim, Goldaru Corp.) 114 mg three times daily for 35 days decreases pain scores, number of lesions, and symptom severity when compared with placebo. However, all patients also used a mouthwash containing betamethasone, diphenhydramine, nystatin, and aluminum-magnesium suspension three times daily (111173).
• Malaria. Although there has been interest in using oral echinacea for malaria, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Migraine headache. Although there has been interest in using oral echinacea for migraine headache, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Otitis media. Oral echinacea does not seem to reduce the rate of recurrence of otitis media in young children, and may actually increase it. Details: Preliminary clinical research shows that taking a specific liquid extract of echinacea fresh roots and dried mature seeds, 0.5 mL three times daily for 3 days at the first sign of a common cold, followed by 0.25 mL three times daily for 7 days, does not prevent otitis media in children 1-5 years of age with a history of recurrent otitis media. In fact, the risk of an episode of otitis media during the 6 month follow-up seemed to increase by 59% in those taking echinacea when compared with placebo (20063).
• Psoriasis. Although there has been interest in using topical echinacea for psoriasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Respiratory tract infections. It is unclear if oral echinacea is beneficial for patients with respiratory tract infections. Details: A large clinical study in adults with respiratory tract infections shows that using echinacea spray or taking echinacea lozenges 16,800 mg daily during days 1-3 and 2240-3360 mg daily afterward for up to 10 days does not improve time to recovery, symptom relief, or number of sick days when compared with echinacea tablets or drops at a prophylactic dose of 2400 mg daily for 10 days. However, the higher dose from days 1-3 is associated with faster viral clearance than the prophylactic dose (111540). The validity of these effects is limited by insufficient blinding and a lack of a placebo group.
• Rheumatoid arthritis (RA). Although there has been interest in using oral echinacea for RA, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Tonsillitis. Oral echinacea has been used with azithromycin to reduce relapses of recurrent tonsillitis in children. A throat spray containing echinacea has also been evaluated for tonsillitis-associated sore throat. It is unclear if echinacea is beneficial for either purpose. Details: Preliminary clinical research in children with recurrent tonsillitis shows that adding echinacea suspension, 250 mg root powder per 5 mL, orally 3 times daily for 10 consecutive days per month for 6 months, to azithromycin 10 mg/kg/day for 6 consecutive days per month for 6 months reduces the number of tonsillitis attacks when compared with azithromycin alone (104127). However, the study was not blinded and the number of tonsillitis episodes in both groups was very low. Other preliminary clinical research shows that applying a throat spray containing sage and echinacea whole plant extract every 2 hours up to 10 times daily for up to 5 consecutive days is as effective as a chlorhexidine-lidocaine spray in patients with sore throat due to acute pharyngitis or tonsillitis (20077).
• Tonsillopharyngitis. Oral echinacea has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized study in patients aged 12-75 years with acute tonsillopharyngitis shows that taking lozenges containing echinacea extract 800 mg and sage extract 5 times daily for 4 days reduces throat pain and tonsillopharyngitis symptoms when compared to baseline, both acutely within 90 minutes and after 4 days of treatment (111530). The validity of these effects is limited by a lack of a comparator group. It is unclear if these effects are due to echinacea, sage, or the combination.
• Upper respiratory tract infection (URTI). It is unclear if oral echinacea is beneficial for preventing or treating URTIs. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients. Another large study in adults with URTIs shows that taking a combination product containing echinacea 1100-2200 mg, zinc, and vitamin C (EZC Pak) daily for 5 days reduces time to recovery by 1.4 days but does not reduce symptom severity when compared with placebo (111512). The validity of these effects is severely limited by multiple instances of selection bias. Additionally, it is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there has been interest in using oral echinacea for UTIs, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Vaginal candidiasis. Although there has been interest in using oral echinacea for vaginal candidiasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Warts. It is unclear if oral echinacea is beneficial for warts when used alone or in combination with other ingredients. Details: Preliminary clinical research shows that taking echinacea 600 mg orally once daily for up to 3 months does not clear common, plantar, or plain cutaneous warts any more effectively than placebo (20080). Other preliminary clinical research shows that taking an oral supplement containing echinacea with methionine, zinc, probiotics, antioxidants and immunostimulants for 6 months, in addition to using conventional topical therapy to treat cutaneous warts, seems to increase the rate of complete remission from 54% to 86% when compared with conventional therapy alone (20071). It is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Water warts. It is unclear if oral echinacea is beneficial for water warts (molluscum contagiosum). Details: In children who have been successfully treated with curettage for molluscum contagiosum, taking a combination of E. angustifolia and E. purpurea orally daily for 2 months is associated with a relapse rate of about 39%, compared with a rate of 68% in a control group that received no oral treatment (104128). The validity of this finding is limited by the lack of a placebo control. E. angustifolia and E. purpurea were taken in doses of 200 mg each in children under 20 kg and 400 mg each in children over 20 kg. More evidence is needed to rate echinacea for these uses.

(Read more about ECHINACEA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Conjunctivitis. Preliminary clinical research shows that applying one drop of eyebright eye drops (WALA Heilmittel GmbH, Eck-walden/Bad Boll) up to five times daily results in complete recovery in about 82% of patients with conjunctivitis after two weeks of treatment (49391). However, due to the lack of a comparator group, it is not clear if this improvement is due to eyebright or to the natural resolution of conjunctivitis symptoms. More evidence is needed to rate eyebright for this use.

(Read more about EYEBRIGHT)

POSSIBLY INEFFECTIVE

• Urine drug tests. Drinking water with goldenseal or adding goldenseal tea to urine does not appear to cause a false negative urine drug screen for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencyclidine, or tetrahydrocannabinol (THC). Details: Goldenseal is often promoted to mask illicit drugs in the urine, but drinking one gallon of water with goldenseal or adding goldenseal tea to urine samples does not seem to cause a false negative immunoassay (EMIT and TDx) for cocaine, amphetamines, barbiturates, benzodiazepines, or opiates. It also does not produce a false negative for Microgenics CEDIA DAU assays for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencyclidine, or THC (260,261,52599). Although adding goldenseal tea to urine samples at 15 grams per liter may produce a false-negative EMIT reading for the presence of THC, the adulteration is obvious due to a brownish color in the urine (52599). Some people also claim that goldenseal can cause a false positive on a drug screen. However, goldenseal does not seem to cause false positives for the fluorescent polarization immunoassay (FPIA) or thin-layer chromatography (TLC) assays for amphetamines, opiates, cocaine, methadone, or their metabolites (2590).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there has been interest in using topical goldenseal for acne, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Allergic rhinitis (hay fever). Although there has been interest in using oral goldenseal for allergic rhinitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Anorexia nervosa. Although there has been interest in using oral goldenseal for anorexia nervosa, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Atopic dermatitis (eczema). Although there has been interest in using topical goldenseal for atopic dermatitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral goldenseal for CFS, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Conjunctivitis. Although there has been interest in using goldenseal as an eye drop for conjunctivitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Dandruff. Although there has been interest in using topical goldenseal for dandruff, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Flatulence. Although there has been interest in using oral goldenseal for flatulence, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Gastritis. Although there has been interest in using oral goldenseal for gastritis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Gingivitis. Although there has been interest in using goldenseal as a mouthwash for gingivitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Hemorrhoids. Although there has been interest in using oral goldenseal for hemorrhoids, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Herpes labialis (cold sores). Although there has been interest in using topical goldenseal for herpes labialis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Menorrhagia. Although there has been interest in using oral goldenseal for menorrhagia, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Otitis media. Although there has been interest in using goldenseal as an ear drop for otitis media, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Peptic ulcers. Although there has been interest in using oral goldenseal for peptic ulcers, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Respiratory tract infections. Although there has been interest in using oral goldenseal for various respiratory tract infections, including influenza, pneumonia, rhinosinusitis, and the common cold, there is insufficient reliable information about the clinical effects of goldenseal for these conditions.
• Tinnitus. Although there has been interest in using goldenseal as an ear drop for tinnitus, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Urinary tract infections (UTIs). Although there has been interest in using oral goldenseal for UTIs, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Uveitis. Although there has been interest in using goldenseal as an eye drop for uveitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Vaginitis. Although there has been interest in using oral goldenseal for vaginitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Wound healing. Although there has been interest in using topical goldenseal for wound healing, there is insufficient reliable information about the clinical effects of goldenseal for this purpose. There is insufficient reliable information available about the effectiveness of goldenseal for its other uses.

(Read more about GOLDENSEAL)

POSSIBLY EFFECTIVE

• Chronic venous insufficiency (CVI). Oral grape leaf extract might improve CVI symptoms. It is unknown if other grape products are beneficial for CVI. Details: Some clinical trials in patients with CVI show that taking a specific grape leaf extract, known as red vine leaf extract (AS 195, Antistax, Boehringer Ingelheim), seems to improve leg edema after 6 weeks of treatment when compared with placebo. Doses of 360 mg and 720 mg daily were both effective, but the higher dose produced a slightly greater effect. Patients also reported decreases in subjective complaints such as tired or heavy legs, tension, and tingling and pain after 2-12 weeks of treatment (2538,52985,53005,53206).

POSSIBLY INEFFECTIVE

• Allergic rhinitis (hay fever). Oral grape seed extract does not seem to improve hay fever symptoms. Details: A clinical study in patients with seasonal allergic rhinitis shows that taking grape seed extract 100 mg twice daily for 8 weeks before ragweed pollen season does not seem to decrease seasonal allergic rhinitis symptoms or antihistamine usage when compared with placebo (9182).
• Chemotherapy-induced nausea and vomiting (CINV). Drinking grape juice does not seem to improve CINV. Details: Clinical research shows that taking 4 ounces of chilled Concord grape juice 30 minutes prior to meals for a week following each of four cycles of chemotherapy does not seem to reduce CINV when compared with placebo (53175).
• Lower urinary tract symptoms (LUTS). Drinking grape juice does not seem to improve LUTS. Details: Clinical research in middle-aged and older men with LUTS shows that drinking 100% Concord grade juice 240 mL daily for 3 months does not improve symptoms when compared with placebo (96190).
• Mastalgia. Oral grape seed extract does not seem to improve mastalgia symptoms. Details: Clinical research in patients treated for early breast cancer using high-dose radiotherapy shows that taking the grape seed extract constituent proanthocyanidin 100 mg orally three times daily for 6 months does not reduce breast tissue hardness, pain, or tenderness when compared with placebo (53048).
• Obesity. Oral grape products do not seem to improve weight loss. Details: Clinical research in overweight or obese individuals shows that drinking Concord grape juice 480 mL daily for 12 weeks does not improve weight or body composition when compared to baseline (53181). Furthermore, taking grape pomace alone or in combination with schisandra fruit extract daily for 4-10 weeks does not improve body composition, abdominal fat, or body weight when compared with control (96200,99269,99270). Taking grape pomace 7-8 grams daily for 4-6 weeks seems to improve insulin resistance by about 33%, but does not affect blood lipids or blood pressure, when compared with placebo in overweight or obese adults with at least one metabolic syndrome factor (99269,99270).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Oral grape skin extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in adults with signs of aging skin shows that taking a specific combination product (Celergen, Laboratories-Dom) containing grape skin extract 10 mg, marine collagen peptides 570 mg, coenzyme Q10 10 mg, luteolin 10 mg, and selenium 0.05 mg, one capsule with breakfast and dinner for 2 months, might improve skin elasticity when compared with baseline. However, there was no effect on moisture or biological skin age (97930). It is not clear if these effects are due to grape skin extract, the other ingredients, or the combination.
• Age-related macular degeneration (AMD). Although there is interest in using oral grape seed for AMD, there is insufficient reliable information about the clinical effects of grape for this condition.
• Atherosclerosis. Oral grape seed extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in postmenopausal adults shows that taking a specific combination product (Karinat, INAT-Farma) containing grape seed extract constituent proanthocyanidin 40 mg, garlic 100 mg, hops 160 mg, green tea 115 mg, vitamin C 30 mg, silicon 8 mg, vitamin E 6.6 mg, and beta-carotene 0.5 mg three capsules daily for 12 months might slow the progression of atherosclerosis as measured by mean carotid intima thickness when compared with placebo. However, the combination product does not seem to affect the growth of existing plaques, and it does not seem to improve lipid parameters (97929). It is not clear if these effects are due to grape seed extract, the other ingredients, or the combination.
• Athletic performance. It is unclear if oral grape products are beneficial for athletic performance. Details: A small study in elite athletes shows that taking a specific grape extract (Powergrape, Naturex SA) 400 mg daily for one month can increase total power in a jumping task when compared with placebo, but has no effect on initial power and maintenance of power (53310). Another small study in recreationally active young adults shows that drinking juice prepared from 46 grams of a freeze-dried preparation of whole grapes daily for 6 weeks prior to a running exercise test does not improve maximal oxygen uptake or work capacity during exercise when compared with placebo (91540).
• Atopic dermatitis (eczema). Topical grape products have only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with atopic dermatitis shows that twice daily application with a cream containing grape polyphenols, vitamin E, and epigallocatechin gallate for 28 days does not improve symptoms or reduce the affected area based on physician assessment when compared with placebo (96196).
• Attention deficit-hyperactivity disorder (ADHD). Although there is interest in using oral grape seed for ADHD, there is insufficient reliable information about the clinical effects of grape for this condition.
• Canker sores. Although there is interest in using oral grape seed for canker sores, there is insufficient reliable information about the clinical effects of grape for this condition.
• Cardiovascular disease (CVD). It is unclear if oral grape products are beneficial for reducing CVD risk. Details: There is preliminary evidence that taking grape products, such as purple grape juice or red grape juice concentrate, might improve endothelium-dependent vasodilation, prevent low-density lipoprotein (LDL) oxidation, reduce markers of inflammation, and suppress platelet-mediated thrombosis. Theoretically, chronic ingestion of these products might reduce the risk of CVD in various patient populations, including adults with type 2 diabetes or hypercholesterolemia, those undergoing hemodialysis, and children with metabolic syndrome (8745,8746,52954,53030,53062,53106,53155,53174). However, a large meta-analysis shows that although taking grape products, including grape extract, grape juice, raisins, and grape seed extract, reduces levels of blood fats by a small amount in a mixed population of adults, these effects were not present in a subgroup of patients with CVD when compared with placebo. There was a small benefit on total cholesterol and high-density lipoprotein (HDL) cholesterol (102610).
• Cognitive function. It is unclear if oral grape products improve cognitive function. Details: Clinical research in healthy adults aged 55-75 years with no cognitive decline shows that taking a specific grape fruit extract (Cognigrape, Bionap srl) 250 mg daily for 12 weeks improves cognitive functioning by 4.5%, and overall neuropsychological status, including attention, language, and recall, by 6%, compared with no change in the placebo group (96198). Also, a preliminary clinical study in middle-aged women under moderate stress shows that drinking Concord grape juice 355 mL daily for 12 weeks improves immediate spacial memory and may improve executive function and verbal recall when compared with placebo (96195).
• Cognitive impairment. Small clinical studies suggest that oral grape products may not slow cognitive decline in older patients with cognitive impairment. Details: One very small study in in patients with mild cognitive decline shows that taking a freeze-dried grape powder 36 grams twice daily for 6 months does not improve most measures of cognitive function and memory, including immediate memory, delayed memory, speed of information processing, cognitive ability, or language, when compared with placebo (96199). Another very small study in older adults with signs of memory decline shows that drinking 100% Concord grape juice 6-9 mL/kg daily for 12 weeks does not improve delayed verbal recall or spatial memory when compared with placebo, although it does seem to moderately improve verbal learning (53166).
• Colorectal cancer. Oral grape seed extract is has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with colorectal cancer shows that taking a product containing grape seed extract, turmeric extract, fermented soybean extract, green tea extract, spirulina, and Taiwanofungus camphoratus, 1920 mg three times daily for 16 weeks during a chemotherapy regimen might modestly increase the effectiveness of treatment when compared with placebo. No patients in the treatment group experienced disease progression, compared with 15.8% (6 patients) of the placebo group. However, there was no significant effect on overall survival or the best response to treatment (96183).
• Constipation. Although there is interest in using oral grape products for constipation, there is insufficient reliable information about the clinical effects of grape for this condition.
• Dental caries. Although there is interest in using topical grape seed for dental caries, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Diabetes. Oral grape extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large clinical study of males with type 2 diabetes mellitus and erectile dysfunction suggests that an oral combination product containing alpha lipoic acid, Gingko biloba, and grape extract (Blunorm Forte, Uriach S.p.A.) taken for 3 months may decrease fasting plasma glucose and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score both alone and when combined with avanafil when compared with baseline and placebo (110707).
• Diabetic retinopathy. It is unclear if oral grape seed extract is beneficial in patients with diabetic retinopathy. Details: A preliminary clinical study in patients with non-proliferative diabetic retinopathy shows that taking a specific grape seed proanthocyanidin extract (Entelon, Hanlim Pharm) 50 mg three times daily for 12 months reduces the severity of hard exudates when compared with calcium dobesilate or placebo. Grape seed extract had a treatment success rate 3-fold and 5.5-fold higher than those of calcium dobesilate and placebo, respectively. Treatment success was defined as a 2-grade decrease in hard exudate severity. No significant improvements in retinopathy grade or visual acuity were reported (100954). However, the study may not have been adequately powered to detect a difference in these outcomes.
• Erectile Dysfunction (ED). Oral grape extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large study of males with type 2 diabetes mellitus and erectile dysfunction suggests that a specific combination product containing alpha lipoic acid, grape extract, and gingko biloba (Blunorm Forte, Uriach S.p.A.) administered orally for three months with avanafil prior to sexual acts improves International Index of Erectile Function (IIEF) scores when compared with either product alone, placebo, and baseline, and may reduce markers of ED including high sensitivity-c-reactive protein, nitrates/nitrites, and metalloproteinases-2 and -9. These results suggest that an oral combination nutraceutical consisting of alpha lipoic acid, grape extract, and gingko biloba (Blunorm Forte, Uriach S.p.A.) may react synergistically with avanafil to enhance sexual performance in males with type 2 diabetes and erectile dysfunction. It is unclear if this effect is due to the alpha lipoic acid, grape extract, or gingko biloba, but researchers theorize that it may be due to the inhibition of phosphodiesterase-5 enzymes by grape extract (110707).
• Hemorrhoids. Although there is interest in using oral grape seed for hemorrhoids, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Hypercholesterolemia. Small clinical studies suggest that oral grape products reduce cholesterol levels by a small amount. Details: A large meta-analysis of heterogeneous clinical trials shows that taking grape products, including grape extract, grape juice, raisins, or grape seed extract, for 2-54 weeks reduces levels of total and low-density lipoprotein (LDL) cholesterol, as well as triglycerides, by a small amount when compared with placebo in a mixed population of adults. In a sub-group of patients with any hyperlipidemia, the mean decreases in LDL cholesterol and triglycerides were 11 mg/dL and 14 mg/dL, respectively. There was no effect on levels of high-density lipoprotein (HDL) in the mixed population or in adults with hyperlipidemia (102610). Although some individual studies disagree, the most evidence for benefit is related to use of whole grape extract or grape seed extract. It is not clear if benefit is dependent on dose or duration of use. These results suggest a benefit of grape products in patients with hypercholesterolemia, but any benefit is likely to be small (42585,96816,102610).
• Hypertension. Some research suggests that oral grape products may modestly lower blood pressure; however, results are inconsistent. Details: Some clinical trials have shown modest benefit in patients with prehypertension, mild hypertension, or metabolic syndrome (18228,53149,96197), but conflicting results exists (91541,90079). A 2016 meta-analysis including 16 trials of 810 patients shows that when compared with placebo, grape seed extract or polyphenols reduces systolic blood pressure (SBP) and diastolic blood pressure (DBP) by about 6 mmHg and 3 mmHg, respectively, with greatest improvements observed in those with obesity or metabolic syndrome. This meta-analysis suggests that a minimum treatment duration of 8 weeks may be necessary before benefit is seen (96194). However, other research in adults with hypertension shows that taking grape seed polyphenols 1000 mg daily for 6 weeks does not alter blood pressure. Also, when grape seed polyphenols were combined with vitamin C 500 mg daily, some patients experienced an increase in blood pressure and worsening of nighttime and daytime variation in blood pressure (13162,90079). The reason for these conflicting findings is unclear but may due to patient characteristics and comorbidities. A meta-analysis of clinical research in various patient populations shows that taking grape seed extract 150-2100 mg for 2-25 weeks improves DBP and heart rate when compared with control, but does not improve SBP or flow-mediated dilation, regardless of dose, duration, sex, BMI, or health status. Additionally, subgroup analyses suggest that blood pressure effects may be greater in patients who are otherwise healthy, female, overweight, and/or under 50 years of age. Also, the use of lower doses and longer treatment durations may be associated with greater benefit (108090). The validity of these findings is limited by the high heterogeneity of included studies. A clinical study in adults with mildly elevated blood pressure shows that a specific grape seed extract (Enovita; Indena SpA) standardized to provide at least 95% oligomeric proanthocyanins, taken as 150 mg twice daily for 16 weeks, does not reduce SBP or DBP when compared with placebo. However, a subgroup analysis suggests that taking grape seed extract improves blood pressure in males, but not in females, when compared with placebo (108091). Some research has also evaluated the effects of grape juice on blood pressure. Two clinical studies in patients with hypertension show that drinking grape juice can reduce blood pressure when compared to baseline; however, another study shows that drinking grape juice does not reduce blood pressure when compared with placebo in these patients (53018,53156,53199).
• Melasma. It is unclear if oral grape seed extract is beneficial in patients with melasma. Details: A very small clinical study in Japanese females with melasma shows that taking grape seed extract (Gravinol, Kikkoman Co) containing 54 mg of proanthocyanidins three times daily for 6-11 months reduces skin hyperpigmentation when compared to pretreatment (53016). The validity of this finding is limited by the lack of a control group.
• Menopausal symptoms. It is unclear if oral grape seed extract is beneficial in patients with menopausal symptoms. Details: Preliminary clinical research in adults with at least one menopausal symptom shows that taking grape seed extract (Gravinol, Kikkoman Biochemifa Co) containing proanthocyanidin 200 mg daily for 8 weeks reduces anxiety when compared with placebo. It also reduces hot flashes and other physical symptoms when compared to baseline, but not when compared with placebo. A lower dose of proanthocyanidin 100 mg daily does not appear to improve these outcomes. Neither doses improved insomnia or depression (91542).
• Metabolic syndrome. Small studies suggest that various oral grape products might improve lipid levels and blood pressure in patients with metabolic syndrome. Details: A meta-analysis of small clinical studies in adults with type 2 diabetes or metabolic syndrome shows that taking grape products, usually grape seed or grape extract, for 4-48 weeks reduces levels of total and low-density lipoprotein (LDL) cholesterol, as well as triglycerides, by a small amount when compared with placebo. The mean decreases in LDL cholesterol and triglycerides were 2.6 mg/dL and 11 mg/dL, respectively (102610). These findings are limited by significant heterogeneity of the included research. Also, a small clinical study in overweight or obese adults, most with metabolic syndrome, shows that taking grape pomace 8 grams daily for 6 weeks improves insulin resistance by about 33%, but does not affect blood lipids, blood pressure, or fasting glucose, when compared with placebo (99270). Some grape products have also shown benefit for improving blood pressure in patients with metabolic syndrome. One small clinical crossover study in males with metabolic syndrome shows that taking 46 grams daily of a freeze-dried, dehydrated preparation of grape polyphenols (equivalent to about 250 grams of fresh grapes daily) for 30 days seems to modestly lower systolic, but not diastolic, blood pressure, and increase brachial artery flow-mediated dilation (FMD) when compared with placebo (18228). Also, a small clinical study in adolescents with metabolic syndrome suggests that drinking natural grape juice 18 mL/kg daily for one month improves FMD when compared with baseline (53174).The validity of this finding is limited by the lack of a control group. A very small clinical study in patients with metabolic syndrome shows that taking a specific grape seed extract (Meganatural BP, Polyphenolics) 150-300 mg daily for 4 weeks modestly reduces blood pressure when compared with placebo (53149). The validity of this finding is limited due to small study size and because patients in the treatment groups had higher blood pressure at baseline.
• Minor bleeding. Topical grape vine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that topically applying 4 mL of a specific product (Ankaferd blood stopper) containing grape vine, alpinia, licorice, thyme, and stinging nettle reduces bleeding, but does not improve the surgical time for episiotomy repair, when compared with saline (31010). It is unclear if this effect is due to grape vine, other ingredients, or the combination.
• Muscle soreness. It is unclear if oral grape products improve muscle soreness. Details: One small study in active young adults shows that drinking juice, prepared from 46 grams of freeze-dried whole grapes, daily for 6 weeks prior to an eccentric arm exercise test does not reduce muscle inflammation or pain at 24 or 48 hours post-exercise when compared with placebo (91540).
• Night vision. Although there is interest in using oral grape seed extract for improving night vision, there is insufficient reliable information about the clinical effects of grape for purpose.
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral grape seed extract reverses fatty liver in patients with NAFLD. Details: One small clinical study in adults with NAFLD shows that taking grape seed extract 1000 mg twice daily for 3 months improves some, but not all, markers of liver damage and improves the grade of fatty liver change when compared with vitamin C supplementation (53190).
• Ocular stress. Although there is interest in using oral grape seed extract for ocular stress, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Premenstrual syndrome (PMS). Although there is interest in using oral grape seed extract for PMS, there is insufficient reliable information about the clinical effects of grape for this condition.
• Wound healing. Limited research suggests that topical grape seed extract might improve wound healing. Details: A small clinical study in adults undergoing surgical removal of minor skin lesions shows that applying red grape seed extract 2% cream twice daily to the affected areas reduces the time to complete wound healing by about 6 days when compared with a placebo cream (91539). Also, preliminary clinical research in patients recovering from cesarean section shows that applying grape seed extract 5% ointment twice daily to cesarean section wounds for 14 days improves wound healing, as measured by a scoring system assessing redness, edema, ecchymosis, discharge, and wound closure, when compared with a placebo ointment. A 2.5% ointment did not improve wound healing measures when compared with placebo (100955). More evidence is needed to rate grape for these uses.

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POSSIBLY EFFECTIVE

• Diabetes. Oral stinging nettle seems to improve glycemic control in patients with diabetes. Details: A meta-analysis of 8 small heterogeneous clinical trials in adults with type 2 diabetes shows that taking stinging nettle 1.5-10 grams in divided doses daily for 8-12 weeks reduces fasting blood glucose (FBG) by 18 mg/dL when compared with placebo (102865). Glycated hemoglobin (HbA1c) was not improved, but the study durations were not adequate to detect an improvement in this measure. Despite positive results on FBG, taking stinging nettle does not seem to improve insulin secretion or measures of insulin sensitivity (91519,102865,108903). Another meta-analysis of 3 small clinical studies in adults with type 2 diabetes shows that taking stinging nettle reduces HbA1c by about 1.3% when compared with placebo. This analysis also suggests stinging nettle reduces post-prandial blood glucose by about 114 mg/dL; however, this is based on a single study. Stinging nettle did not improve fasting blood glucose or insulin resistance in this analysis (111503). The validity of these findings is limited by the low quality and heterogeneity of included studies, as well as unclear dosing. Furthermore, since most research has been conducted in Iran, it is unknown if these findings are generalizable to other geographic locations. Stinging nettle has also been used in combination with other natural medicines. One small clinical study in adults with type 2 diabetes shows that taking a product containing stinging nettle leaf extract 200 mg, milk thistle 200 mg, and Boswellia serrata gum 200 mg three times daily for 3 months reduces FBP by about 28 mg/dL and HbA1c by about 1.5%, compared with a smaller reduction in the placebo group (96742). It is unclear if this effect is due to stinging nettle, the other ingredients, or the combination.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if oral stinging nettle is beneficial for hay fever. Details: Taking stinging nettle leaf extract 300 mg 3-7 times daily at the first sign of hay fever symptoms seems to provide subjective improvement (7035). However, adding stinging nettle to conventional allergy medication might not provide any additional benefit. One small clinical study shows that adding stinging nettle tablets (Urtidin, Barij Essence Pharmaceutical Co.) 150 mg four times daily for 1 month to treatment with loratadine and nasal saline rinses does not improve symptoms of allergic rhinitis when compared with placebo with loratadine and nasal saline rinses (96743).
• Anemia. Although there is interest in using oral stinging nettle for anemia, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Asthma. Although there is interest in using oral stinging nettle for asthma, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Benign prostatic hyperplasia (BPH). It is unclear if oral stinging nettle is beneficial for BPH. Details: A meta-analysis of clinical research, including 5 clinical studies and 1,128 patients with BPH, shows that taking stinging nettle root extract 360-600 mg in divided doses daily for 2-12 months improves peak urinary flow rate and symptom scores while modestly reducing prostate volume when compared with control. However, the validity of these results is limited by significant heterogeneity due to the variability in the products used and the specific endpoints investigated (96744). In the largest clinical trial in the analysis, patients took stinging nettle root extract 120 mg three times daily for 6 months (76406). Stinging nettle has also been evaluated in combination products. Clinical research in patients with BPH shows that taking a specific combination product (PRO 160/120, Dr. Willmar Schwabe Pharmaceuticals) containing a specific extract of stinging nettle root (WS 1031) 120 mg plus a specific extract of saw palmetto fruit (WS 1473) 160 mg twice daily for 24-48 weeks seems to improve urinary tract symptoms when compared with control; the effect may last at least 48 weeks after treatment (15195,15551,76409). However, taking a different combination product does not seem to be beneficial. A small clinical study in patients with BPH shows that taking a product containing stinging nettle root extract 240 mg, saw palmetto, pumpkin seed oil, lemon bioflavonoid, and beta-carotene, three times daily for 6 months, does not improve symptoms of BPH (5093).
• Bleeding. Topical stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some preliminary clinical research shows that applying 4 mL of a specific product (Ankaferd blood stopper, Mefar Ilaç Sanayi A.S) containing alpinia, licorice, thyme, stinging nettle, and common grape vine to the affected area reduces bleeding, but does not improve the time for episiotomy repair, when compared with using saline (31010).
• Gingivitis. Stinging nettle in a mouthwash solution has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with moderate gingival inflammation suggests that using 10 mL of mouthwash solution containing a 1:1:1 mixture of stinging nettle, juniper, and yarrow twice daily for 3 months does not reduce plaque or bleeding when compared with control (76443). It is not clear if this effect is due to stinging nettle, the other ingredients, or the combination.
• Gout. Although there is interest in using oral stinging nettle for gout, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Gulf war syndrome. It is unclear if oral stinging nettle is beneficial for Gulf war syndrome. Details: A very small exploratory clinical trial in males with Gulf war syndrome shows that taking stinging nettle leaf (Nature's Way) 1305 mg in two divided doses daily for 30 days modestly improves symptom severity when compared with placebo (108311). The clinical relevance of this finding is limited by the use of an unvalidated scoring scale. Additionally, it appears that most patients had mild, unspecified symptoms at baseline; it is unclear if stinging nettle is beneficial for moderate to severe symptoms.
• Hyperandrogenism. It is unclear if oral stinging nettle is beneficial in patients with hyperandrogenism. Details: Preliminary clinical research in females with hyperandrogenism shows that taking dried extract of stinging nettle root 300-600 mg daily for approximately 4 months decreases total and free testosterone levels, but not menstrual cycle conditions, oily skin, or acne, when compared with taking spironolactone and cyproterone (91520).
• Insect bite. Oral stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that applying a homeopathic after-bite gel, containing stinging nettle, Echinacea, and marsh Labrador tea, on affected areas does not reduce erythema or itching after a mosquito bite when compared with placebo (89235).
• Kidney stones (nephrolithiasis). Although there is interest in using oral stinging nettle for kidney stones, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Myalgia. Although there is interest in using topical stinging nettle for myalgia, there is insufficient reliable information about the clinical effects of stinging nettle for this purpose.
• Osteoarthritis. Small clinical studies suggest that topical stinging nettle may modestly improve pain in patients with osteoarthritis. It is unclear if oral stinging nettle is beneficial. Details: Topically, stinging nettle leaf may have a counterirritant effect which may improve osteoarthritis pain in some patients. A small clinical study in patients ages 45-82 with osteoarthritis of the thumb shows that applying raw stinging nettle leaf to the thumb for 30 seconds daily for 1 week reduces pain and disability when compared with white dead nettle leaf control (12490). However, in another small clinical study in patients with knee osteoarthritis, topical application of raw stinging nettle leaf to the knee for 1 minute daily for 7 days does not seem to be more effective for reducing pain than applying a leaf from a related stingless nettle (76412). Non-raw stinging nettle has also been tried. In a small open-label study, a formulation of stinging nettle extract (Liquid PhytoCaps Nettle Leaf, Gaia Herbs) 13.33% compounded with lipobase oil-in-water emulsion and applied to the affected area twice daily for 2 weeks, modestly improves pain and function in patients with radiologically confirmed osteoarthritis when compared with baseline (76414). The validity of this finding is limited by the lack of a comparator group. Stinging nettle has also been evaluated orally, in combination with other ingredients. A clinical study in adults with knee osteoarthritis shows that taking a specific combination solution (Rosaxan, medAgil Gesundheitsgesellschaft mbH) containing stinging nettle extract 160 mg, rose hip puree 20 grams, devil's claw 108 mg, and vitamin D 200 IU daily for 12 weeks improves symptoms by an additional 28% and pain scores by an additional 33% when compared with placebo (96741). It is unclear if this effect is due to stinging nettle, the other ingredients, or the combination.
• Tinnitus. Oral stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with tinnitus shows that taking a specific product containing stinging nettle, tansy, and rose hip (Neurotec, Rose Pharmed), 100 mg orally daily for 3 months does not improve auditory thresholds when compared with placebo. However, the product improved some subjective symptoms scores, such as perceived loudness and severity scores (110512).
• Urinary tract infections (UTIs). Although there is interest in using oral stinging nettle for UTIs, there is insufficient reliable information about the clinical effects of stinging nettle for this condition. More evidence is needed to rate stinging nettle for these uses.

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LIKELY SAFE ...when used orally and appropriately, short-term. Various liquid extracts of Echinacea purpurea have been used safely for up to 10 days, including EchinaGuard (Madaus AG) 20 drops every 2 hours for 1 day, then three times daily (10320), or Echinilin (Inovobiologic Inc.) 40 mL in divided doses for 1 day, then 15 mL in divided doses daily thereafter (12355,20062). Other liquid extracts have been used safely for relatively longer periods, including Echinaforce (A. Vogel Bioforce AG) 2.4 grams daily for 4 months or 1.6 grams daily for 6 months (7087,18225), and Echinacin (Madaus AG) 5 mL twice daily for 10 days, or 4 mL twice daily for 8 weeks (3282,10802). Specific solid dosage forms of echinacea that have been used safely for up to 10 days include Echinacea purpurea above-ground parts (EchinaFresh, Enzymatic Therapy) 300 mg daily (11970), and mixtures of Echinacea purpurea and Echinacea angustifolia herb in divided doses of 6 grams to 10.5 grams for 1 day then 3 grams to 5.1 grams daily (10800,17519,20059). A specific Echinacea angustifolia extract (ExtractumPharma ZRT) has also been used with apparent safety at a dose of 40 mg once or twice daily for up to 7 days (20064,103233). An Echinacea purpurea product (Natures Resource) has been used safely at a dose of 1.8 grams daily for 8 weeks (17521), and echinacea (Puritan's Pride) has been used safely at 8 grams daily for 28 days (20066).

POSSIBLY SAFE ...when used topically, short-term. A specific cream (Linola Plus Cream, Dr. August Wolff GmbH & Co.) containing echinacea extract (WO 3260) has been applied to the skin safely 2-3 times daily for up to 12 weeks (97499). There is insufficient reliable evidence about the safety of echinacea when used parenterally.

CHILDREN: POSSIBLY SAFE
when used orally, short-term. Some clinical research shows that an extract of the above-ground parts of Echinacea purpurea (EC31J2, Echinacin Saft, Madaus AG) in a dose of 3.75 mL twice daily (for ages 2 years to 5 years) or 7.5 mL twice daily (for ages 6 years to 11 years) is safe when used for up to 10 days (4989). However, about 7% of children experienced a rash after taking echinacea, which might have been caused by an allergic reaction (4989). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). In contrast, another clinical study in children 4-12 years old shows that a specific Echinacea purpurea product (Echinaforce Junior, A. Vogel) does not cause allergic or urticarial reactions more frequently than vitamin C (105719).

PREGNANCY: POSSIBLY SAFE
when used orally, short-term. There is preliminary evidence that mothers can safely use echinacea in the form of E. purpurea or E. angustifolia solid dosage forms, 250-1000 mg daily, or tinctures, up to 30 drops daily, for 5 days to 7 days during the first trimester without adversely affecting the fetus (7056,13418,15123). There is insufficient reliable information available about the safety of echinacea when used for longer than 7 days.

LACTATION:
Insufficient reliable information available; avoid using.

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LIKELY SAFE ...when used orally in amounts commonly found in foods. Eyebright is listed by the Council of Europe as a natural source of food flavoring (4).

POSSIBLY UNSAFE ...when applied into the eyes. Avoid using due to hygienic concerns; eyebright ophthalmic products may be subject to contamination (8,11). There is insufficient reliable information available about the safety of eyebright when used orally in medicinal amounts.

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

(Read more about EYEBRIGHT)

POSSIBLY SAFE ...when used orally and appropriately as a single dose (260,261). There is insufficient reliable information available about the safety of goldenseal when used as more than a single dose.

CHILDREN: LIKELY UNSAFE
when used orally in newborns. The berberine constituent of goldenseal can cause kernicterus in newborns, particularly preterm neonates with hyperbilirubinemia (2589).

PREGNANCY: LIKELY UNSAFE
when used orally. Berberine is thought to cross the placenta and may cause harm to the fetus. Kernicterus has developed in newborn infants exposed to goldenseal (2589).

LACTATION:
LIKELY UNSAFE when used orally. Berberine and other harmful constituents can be transferred to the infant through breast milk (2589). Use during lactation can cause kernicterus in the newborn and several resulting fatalities have been reported (2589).

(Read more about GOLDENSEAL)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Grapes and grape skin extracts have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

POSSIBLY SAFE ...when the whole fruit of the grape, or extracts of the fruit, seed, or leaf, are used orally and appropriately in medicinal amounts. Grape seed extracts have been used with apparent safety in doses up to 200 mg daily for up to 11 months (9182,53016) and in doses up to 2000 mg daily for up to 3 months (53149,53190). Specific grape fruit extracts (Stilvid, Actafarma; Cognigrape, Bionap srl) have been used with apparent safety in doses up to 250-350 mg daily for 3-12 months or 700 mg daily for 6 months (53254,53256,96198). A specific grape leaf extract (AS 195, Antistax, Boehringer Ingelheim) has been used with apparent safety in doses up to 720 mg daily for up to 3 months (2538,52985,53005,53206). A preparation of dehydrated whole grapes, equivalent to 250 grams of fresh grapes daily, has also been used with apparent safety for up to 30 days (18228). A specific grape seed extract (Enovita; Indena SpA) 150 mg twice daily, standardized to provide at least 95% oligomeric proanthocyanins, has been used with apparent safety for up to 16 weeks (108091) ...when used topically and appropriately. Creams and ointments containing grape seed extract 2% or 5% have been used topically with apparent safety for up to 3 weeks (91539,100955). There is insufficient reliable information available about the safety of other grape plant parts when used topically.

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods. Grapes and grape skin extracts have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912). However, whole grapes should be eaten with caution in children aged 5 years and under. Whole grapes can be a choking hazard for young children (96193). To reduce the risk of choking, whole grapes should be cut in half or quartered before being given to children. There is insufficient reliable information available about the safety of grape when used in medicinal amounts in children.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of medicinal amounts during pregnancy and breast-feeding; avoid using in amounts greater than what is commonly found in foods.

(Read more about GRAPE)

POSSIBLY SAFE ...when used orally and appropriately. Stinging nettle root 360-600 mg has been used safely for up to 1 year (5093,11230,15195,76406,96744). ...when used topically and appropriately (12490).

PREGNANCY: LIKELY UNSAFE
when used orally due to possible abortifacient and uterine-stimulant effects (4,6,19).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about STINGING NETTLE)

CAFFEINE Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Echinacea can increase plasma levels of caffeine by inhibiting its metabolism.  Details Echinacea seems to increase plasma concentrations of caffeine by around 30% (12155). This is likely due to inhibition of cytochrome P450 1A2 (CYP1A2) by echinacea.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.  Details Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30% (12155). Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.  Details Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir (13712,48618,88164,88165). However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4 (48618). The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4 (12155). In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate (6450,11026,88162,88167).

DARUNAVIR (Prezista) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of darunavir; however, a small clinical study found no effect.  Details Darunavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but administration of an E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg four times daily for 14 days did not affect darunavir/ritonavir pharmacokinetics in 15 HIV-infected patients (88163,93578).

DOCETAXEL (Taxotere) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of docetaxel; however, a small clinical study found no effect.  Details Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea whole plant extract (Echinaforce, A. Vogel Biopharma AG) 20 drops three times daily for 2 weeks did not alter the pharmacokinetics of docetaxel in one clinical study (88164).

ETOPOSIDE (VePesid) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Echinacea may increase levels of etoposide.  Details In one report, concomitant use of etoposide and echinacea was associated with more severe thrombocytopenia than the use of etoposide alone, suggesting inhibition of etoposide metabolism (20082). Etoposide is a cytochrome P450 3A4 (CYP3A4) substrate. Echinacea has variable effects on CYP3A4, but some studies have reported inhibition of the enzyme (6450,11026,12155,88162,88167).

ETRAVIRINE (Intelence) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of etravirine; however, a small clinical study found no effect.  Details Etravirine is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg three times daily for 14 days did not alter the pharmacokinetics of etravirine in HIV-infected patients (88165,93578).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Echinacea has immunostimulant activity which may interfere with immunosuppressant therapy.  Details Theoretically, echinacea may interfere with immunosuppressant therapy because of its immunostimulant activity (3279,6388,6389,12639).

LOPINAVIR/RITONAVIR (Kaletra) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of lopinavir; however, a small clinical study found no effect.  Details Lopinavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but taking E. purpurea (Echinamide, Natural Factors Nutritional Products, Inc.) 500 mg three times daily for 14 days did not alter the pharmacokinetics of lopinavir/ritonavir in healthy volunteers (48618,93578).

MIDAZOLAM (Versed) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Theoretically, echinacea may increase the metabolism of intravenous midazolam.  Details Echinacea induces hepatic CYP3A4 and might decrease plasma levels of midazolam by about 20%, reducing the effectiveness of intravenous midazolam (12155). Echinacea also appears to inhibit intestinal CYP3A4, which could theoretically increase the bioavailability of oral midazolam. This may cancel out the decrease in availability caused by induction of hepatic CYP3A4, such that overall plasma levels after oral administration of midazolam are not affected by echinacea.

WARFARIN (Coumadin) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Echinacea seems to increase the clearance of warfarin, although the effect may not be clinically significant.  Details Preliminary clinical research in healthy male volunteers suggests that taking echinacea increases the clearance of the active S-isomer of warfarin after a single dose of warfarin, but there was not a clinically significant effect on the INR (20083).

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ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.  Details Goldenseal contains berberine. In vitro and animal research shows that berberine can inhibit platelet aggregation (33660,33694). However, this effect has not been reported in humans.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of hypoglycemia when used with antidiabetes drugs.  Details Goldenseal contains berberine. Clinical research shows that berberine can lower blood glucose levels (20579,34247,34265,34282). However, this effect has not been reported with goldenseal.

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of hypotension when taken with antihypertensive drugs.  Details Goldenseal contains berberine. Animal research shows that berberine can have hypotensive effects (33692,34308). Also, an analysis of clinical research shows that taking berberine in combination with amlodipine can lower systolic and diastolic blood pressure when compared with amlodipine alone (91956). However, this effect has not been reported with goldenseal.

CNS DEPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the sedative effects of CNS depressants.  Details Goldenseal contains berberine. Animal research shows that berberine can have sedative effects (13519,33650,33664,33692). However, this effect has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2C9.  Details In vitro research shows that goldenseal root extract can modestly inhibit CYP2C9. This effect may be due to its alkaloid constituents, hydrastine and berberine (21117). However, this effect has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Goldenseal might increase serum levels of drugs metabolized by CYP2D6.  Details Clinical and in vitro research shows that goldenseal can significantly inhibit CYP2D6 enzymes, potentially increasing levels of drugs metabolized by CYP2D6 (13536,16848,35907).

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2E1.  Details In vitro research shows that goldenseal root extract can inhibit the activity of CYP2E1 (94140). However, this effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Goldenseal might increase serum levels of drugs metabolized by CYP3A4.  Details Most clinical and in vitro research shows that goldenseal inhibits CYP3A4 enzyme activity and increases serum levels of CYP3A4 substrates, such as midazolam (6450,13536,21117,91740,111725). However, in one small clinical study, goldenseal did not affect the levels of indinavir, a CYP3A4 substrate, in healthy volunteers (10690,93578). This is likely due to the fact that indinavir has a high oral bioavailability, making it an inadequate probe for CYP3A4 interactions (13536,91740) and/or that it is primarily metabolized by hepatic CYP3A, while goldenseal has more potential to inhibit intestinal CYP3A enzyme activity (111725). Both goldenseal extract and its isolated constituents berberine and hydrastine inhibit CYP3A, with hydrastine possibly having more inhibitory potential than berberine (111725).

DEXTROMETHORPHAN (Robitussin DM, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of dextromethorphan.  Details Goldenseal contains berberine. A small clinical study shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan (34279).

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Goldenseal might increase serum levels of digoxin, although this effect is unlikely to be clinically significant.  Details Clinical research shows that goldenseal modestly increases digoxin peak levels by about 14% in healthy volunteers. However, goldenseal does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC) (15132). This suggests that goldenseal does not cause a clinically significant interaction with digoxin. Digoxin is a P-glycoprotein substrate. Some evidence suggests that goldenseal constituents might affect P-glycoprotein; however, it is unclear whether these constituents inhibit or induce P-glycoprotein.

LOSARTAN (Cozaar) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might decrease the conversion of losartan to its active form.  Details Goldenseal contains berberine. A small clinical study shows that berberine inhibits cytochrome P450 2C9 (CYP2C9) activity and reduces the metabolism of losartan (34279). However, this effect has not been reported with goldenseal.

METFORMIN (Glucophage) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might reduce blood levels of metformin.  Details In vitro research shows that goldenseal extract decreases the bioavailability of metformin, likely by interfering with transport, intestinal permeability, or other processes involved in metformin absorption. It is unclear which, if any, of metformin's transporters are inhibited by goldenseal. Goldenseal does not appear to alter the clearance or half-life of metformin (105764).

OSELTAMIVIR (Tamiflu) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.  Details In vitro evidence suggests that goldenseal reduces the formation of the active compound from the prodrug oseltamivir (105765). The mechanism of action and clinical relevance is unclear.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, goldenseal might increase or decrease serum levels of P-glycoprotein (P-gp) substrates.  Details There is conflicting evidence about the effect of goldenseal on P-gp. In vitro research suggests that berberine, a constituent of goldenseal, modestly inhibits P-gp efflux. Other evidence suggests that berberine induces P-gp. In healthy volunteers, goldenseal modestly increases peak levels of the P-gp substrate digoxin by about 14%. However, it does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC) (15132). This suggests that goldenseal is not a potent inhibitor of P-gp-mediated drug efflux. Until more is known, goldenseal should be used cautiously with P-gp substrates.

PENTOBARBITAL (Nembutal) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the sedative effects of pentobarbital.  Details Animal research shows that berberine, a constituent of goldenseal, can prolong pentobarbital-induced sleeping time (13519). However, this effect has not been reported with goldenseal.

TACROLIMUS (Prograf) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of tacrolimus.  Details Goldenseal contains berberine. In a 16-year-old patient with idiopathic nephrotic syndrome who was being treated with tacrolimus 6.5 mg twice daily, intake of berberine 200 mg three times daily increased the blood concentration of tacrolimus from 8 to 22 ng/mL. Following a reduction of tacrolimus dosing to 3 mg daily, blood levels of tacrolimus decreased to 12 ng/mL (91954).

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ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, grape extracts may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.  Details In vitro evidence suggests that grape extracts might decrease platelet aggregation (53017,53087).

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Ingesting grape juice with cyclosporine can reduce cyclosporine absorption.  Details A small pharmacokinetic study in healthy young adults shows that intake of purple grape juice 200 mL along with cyclosporine can decrease the absorption of cyclosporine by up to 30% when compared with water (53177). Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, grape juice might reduce the levels of CYP1A2 substrates.  Details A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of CYP1A2 (2539).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.  Details In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes (11094,53011,53089). However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism (11094). The effects of continued grape juice consumption are unclear.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, grape seed extract may increase the levels of CYP2D6 substrates.  Details In vitro evidence suggests that grape seed extract might inhibit CYP2D6 enzymes (53011). However, this interaction has not been reported in humans.

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, grape seed extract might increase the levels of CYP2E1 substrates.  Details In vitro and animal research suggests that grape seed proanthocyanidin extract inhibits CYP2E1 enzymes (52949). However, this interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.  Details In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes (53089). However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver (53011). So far, these interactions have not been reported in humans.

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, long-term intake of grape seed extract might decrease the effects of midazolam.  Details Animal research shows that subchronic ingestions of grape seed extract can increase the elimination of intravenous midazolam by increasing hepatic CYP3A4 activity. Single doses of grape seed extract do not appear to affect midazolam elimination (53011).

PHENACETIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Grape juice might decrease phenacetin absorption.  Details A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of cytochrome P450 1A2 (CYP1A2) (2539).

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, stinging nettle might have additive effects with antidiabetes drugs.  Details Clinical research shows that stinging nettle might decrease blood glucose levels in patients with diabetes (91519,102865).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, combining stinging nettle with diuretic drugs may have additive effects.  Details Animal research suggests that the above ground parts and roots of stinging nettle may have a diuretic effect (1,4,11,76402).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, stinging nettle might reduce excretion and increase levels of lithium.  Details Animal research suggests that stinging nettle has diuretic and natriuretic properties, which could alter the excretion of lithium (76402). The dose of lithium might need to be decreased.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D There is some concern that stinging nettle might decrease the effects of anticoagulant drugs such as warfarin.  Details Stinging nettle contains a significant amount of vitamin K (19). When taken in large quantities, this might interfere with the activity of warfarin.

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General ...Orally, echinacea is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, constipation, diarrhea, heartburn, nausea and vomiting, rashes, and stomach upset.
Serious Adverse Effects (Rare):
Orally: Severe allergic reactions and hepatitis have been reported.

Dermatologic ...Itching, urticaria, tingling, and allergic rashes have been reported with various echinacea preparations (8225,12355,17519,20059,20077,101592,111530,111540). In a study of children aged 2-11 years, rash occurred in about 7% of children treated with an extract of the above-ground parts of E. purpurea (EC31J2, Echinacin Saft, Madaus AG), compared with about 3% of those treated with placebo (4989,95652). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom (UK) recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). However, another study in children 4-12 years old shows that a specific E. purpurea product (Echinaforce Junior, A. Vogel) did not cause allergic or urticarial reactions more frequently than vitamin C (105719).

Gastrointestinal ...Gastrointestinal adverse effects include nausea and vomiting, abdominal pain, stomach upset, heartburn, diarrhea, and constipation (10802,11970,12355,13419,17519,20059,48680,105719,106626). An unpleasant taste, dry mouth, and burning, tingling or numbness of the tongue also occur (11970,12355,17519,20059,20070,20077).

Hematologic ...A 51-year-old female presented with leukopenia after taking echinacea 450 mg three times daily for 2 months, along with ginkgo biloba, multivitamins, and calcium. Her leukocyte count recovered upon stopping these supplements, but dropped again when she restarted echinacea alone about a year later. The problem resolved when echinacea was stopped permanently (48533). A 32-year-old male presented with severe thrombotic thrombocytopenic purpura (TTP) about 2 weeks after using an extract of E. pallida to treat a cold. He required admission to an intensive care unit and extensive plasmapheresis. The authors speculate that immunostimulant effects of echinacea induced or exacerbated the TTP (48572).

Hepatic ...Although uncommon, cases of echinacea-induced hepatitis have been reported. One case report describes acute cholestatic autoimmune hepatitis in a 45-year-old male who had been taking an echinacea root extract 1500 mg daily for about 2 weeks. He presented with significantly elevated liver function tests (LFTs), elevated immunoglobulin G (IgG) levels, and a positive test for anti-smooth muscle antibodies, indicating an autoimmune process. Elevated LFTs and IgG levels returned to normal within one month of stopping echinacea (17518). Another case report describes acute cholestatic hepatitis in a 44-year-old male who had taken echinacea root tablets 600 mg daily for 5 days to treat flu-like symptoms. He presented with elevated LFTs, prothrombin time, and international normalized ratio (INR). His condition gradually improved after stopping echinacea, and his LFTs normalized within 3 months (91528).
Seven cases of hepatitis associated with echinacea use were reported to the Australian Adverse Drug Reactions Advisory Committee between 1979 and 2000, but specific details are lacking (8225).
One case report describes acute liver failure in a 2 year-old child who had been given about 100 mg of echinacea daily for 2 weeks. The patient presented with jaundice, diarrhea, lethargy, anorexia, and significantly elevated LFTs. A liver biopsy showed hepatocyte swelling, spotty necrosis, and inflammatory infiltrate with eosinophils. A full recovery was made over a 2-week period (88166).

Immunologic ...Allergic reactions, including urticaria, runny nose, dyspnea, bronchospasm, acute asthma, angioedema, and anaphylaxis, have been reported with various echinacea preparations (638,1358,8225). Atopic individuals and those sensitive to other members of the Asteraceae family (ragweed, chrysanthemums, marigolds, daisies) seem to be at higher risk for these reactions (1358,8225).
A case report describes a 36-year-old female who presented with muscle weakness, electrolyte abnormalities, renal tubular acidosis, fatigue, and dry mouth and eyes after taking echinacea, kava, and St. John's Wort for 2 weeks., She also had a positive antinuclear antibody (ANA) test, with elevated anti-dsDNA antibodies SSA and SSB. Sjogren syndrome was diagnosed; the authors hypothesize that it may have been triggered by the immunostimulant effects of echinacea (10319). A 55-year-old male with a history of pemphigus vulgaris in remission for about a year experienced a flare of the disease after taking an echinacea supplement for one week. After stopping echinacea, medical treatment resulted in partial control of the disease (12171). Another case report describes a 58-year-old male who presented with marked eosinophilia and elevated immunoglobulin E (IgE) levels while taking an echinacea supplement. He required prednisone therapy until he stopped taking echinacea 3 years later, at which time his eosinophils and IgE normalized (48623). A 41-year-old male experienced four episodes of erythema nodosum, each occurring after he had taken echinacea for early symptoms of influenza. After stopping echinacea, he had no further exacerbations of erythema nodosum, suggesting that it had been triggered by the immunostimulant effects of echinacea (7057).

Musculoskeletal ...Reports of arthralgia and myalgia have been associated with echinacea (13418).

Neurologic/CNS ...Headache has been reported in people taking various echinacea preparations orally (3282,11970,17519,20059,20064). Dizziness has also been reported (3282,8225,11970). In one study using an alcoholic extract of the above-ground parts of E. purpurea (EC31J0, Echinacin, Madaus AG), somnolence and a tendency to aggressiveness were reported (3282).

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General ...There is a limited amount of information on the adverse effects of eyebright. Orally, eyebright has been reported to cause mental confusion, headache, nausea, constipation, cough, dyspnea, insomnia, and polyuria (4). Topically, eyebright applied to the eye has been reported to cause increased eye pressure, itching, redness, vision changes, and photophobia (4). Ophthalmic eyebright products should be used with caution due to the potential for contamination (8,11).

Gastrointestinal ...Orally, eyebright has been reported to cause nausea and constipation (4).

Genitourinary ...Orally, eyebright has been reported to cause polyuria (4).

Neurologic/CNS ...Orally, eyebright has been reported to cause confusion and headache (4).

Ocular/Otic ...Topically, eyebright has been reported to cause increased ocular pressure, lacrimation, pruritus, redness, swelling of eyelid margins, vision changes, and photophobia when applied to the eyes (4). Ophthalmic eyebright products should be used with caution due to the potential for contamination (8,11).

Pulmonary/Respiratory ...Orally, eyebright has been reported to cause cough, dyspnea, and nasal congestion (4).

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General ...There is limited reliable information available about the safety of goldenseal when used in more than a single dose. Berberine, a constituent of goldenseal, is generally well tolerated when used orally.
Most Common Adverse Effects:
Orally: Berberine, a constituent of goldenseal, can cause abdominal distension, abdominal pain, bitter taste, constipation, diarrhea, flatulence, headache, nausea, and vomiting.

Dermatologic ...Orally, berberine, a constituent of goldenseal, may cause rash. However, this appears to be rare (34285). A case of photosensitivity characterized by pruritic, erythematous rash on sun-exposed skin has been reported in a 32-year-old female taking a combination product containing goldenseal, ginseng, bee pollen, and other ingredients. The rash resolved following discontinuation of the supplement and treatment with corticosteroids (33954). It is not clear if this adverse effect is due to goldenseal, other ingredients, or the combination.

Endocrine ...A case of severe, reversible hypernatremia has been reported in an 11-year-old female with new-onset type 1 diabetes and diabetic ketoacidosis who took a goldenseal supplement (52592).

Gastrointestinal ...Orally, berberine, a constituent of goldenseal, may cause diarrhea, constipation, flatulence, vomiting, abdominal pain, abdominal distention, and bitter taste (33648,33689,34245,34247,34285,91953). Theoretically, these effects may occur in patients taking goldenseal. However, this hasn't been reported in clinical research or case reports.

Neurologic/CNS ...Orally, berberine, a constituent of goldenseal, may cause headache when taken in a dose of 5 mg/kg daily (33648). Theoretically, this may occur with goldenseal, but this hasn't been reported in clinical research or case reports.

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General ...Orally, the whole fruit, as well as the seed, fruit, and leaf extracts, seem to be well tolerated. Topically, grape seed extracts seem to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, diarrhea, dry mouth, dyspepsia, headache, joint pain, and nausea.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis to grape skin has been reported.

Dermatologic ...Orally, mild hair thinning has been reported in a patient taking a specific grape leaf extract AS195 KG) (2538). Urticaria (hives) has also been reported with this same extract (53206). Cases of contact dermatitis have been reported in grape workers, including those working in California vineyards (53270,53272,53275).

Gastrointestinal ...Orally, abdominal pain and nausea have been reported with use of grape seed extract, but these effects typically occur at rates similar to placebo (9182,13162). In a case report of a 57-year-old man, intermittent nausea, vomiting, and diarrhea occurred over a 10-day period and improved once grape seed extract was stopped (96764). Gastrointestinal adverse effects have also been reported with use of a different grape seed extract (Entelon, Hanlim Pharm). However, the specific types of gastrointestinal effects were not described (100954). A specific grape leaf extract AS195 (Antistax, Boehringer Ingelheim Pharma GmbH & Co. KG) has reportedly caused flatulence, mild constipation, gastrointestinal discomfort, diarrhea, dyspepsia, dry mouth, and retching (2538,52985,53206). Diarrhea, gastrointestinal distress, indigestion, and aversion to taste have been reported with use of Concord grape juice (52972,53166,53175,53181,53199). Loose stools have been reported in a clinical trial of grape pomace (99270). Bowel obstruction caused by intact grapes and grape seeds has been described in case reports (53241,53284,53278). Excessive consumption of grapes, dried grapes, raisins, or sultanas might cause diarrhea due to laxative effects (4201).

Hematologic ...Orally, one case of leg hematoma following a minor trauma was reported in a person using grape leaf extract (2538). Also, one case of bruising was reported in a person drinking Concord grape juice daily for 2 weeks (52972).

Immunologic ...Orally, there is one report of an anaphylactic reaction to oral grape skin extract, which included urticaria and angioedema (4073).

Musculoskeletal ...Orally, musculoskeletal disorders, including back pain, have been reported with use of a specific grape leaf extract AS195 KG) (2538,53206). Joint pain and lumbago have been reported with use of grape seed extract, but these effects occur at rates similar to placebo (91541).

Neurologic/CNS ...Orally, headache has been reported with use of grape seed extract, but this effect occurs at rates similar to placebo (9182,91541). A specific grape leaf extract AS195 (Antistax, Boehringer Ingelheim Pharma GmbH & Co. KG) has reportedly caused dizziness, tiredness, headache, and sleep problems (2538,53206). As a class, nervous system adverse effects have been reported with use of a specific grape seed extract (Entelon, Hanlim Pharm). However, the specific types of adverse neurologic effects were not described (100954).

Ocular/Otic ...Orally, ocular adverse effects have been reported with use of a specific grape seed extract (Entelon, Hanlim Pharm). However, the specific types of ocular adverse effects were not described (100954).

Pulmonary/Respiratory ...Orally, nasopharyngitis and oropharyngeal pain have been reported with use of a specific grape leaf extract AS195 KG) (53206). Sore throat, cough, allergic rhinitis, and nasopharyngitis have been reported with use of grape seed extract, but these effects occur at rates similar to placebo (9182,91541). One case report describes a 16-year-old female who developed increased levels of immunoglobulin E (IgE) following skin-prick exposure to grape vine pollen, as well as positive test responses following bronchial and conjunctival provocation (53301). Reduced forced vital capacity has been described in California grape workers (53080,53081). Occupational eosinophilic lung was diagnosed in a grape grower with a history of asthma. Respiratory exposure to sulfites in grape was implicated as the cause of the adverse reaction (53285).

Other ...Orally, grape products can cause adverse effects due to contamination with pesticides or mycotoxins. Some evidence has shown that pesticides used in vineyards may remain on grape surfaces post-harvesting. For example, the fungicide folpet sprayed on grapevines has been shown to remain on the grape surface. Although there was minimal penetration of the epicuticular wax, it showed high resistance to washing (52935). Carbaryl has been identified in over 58% of juice samples collected in Canada. This pesticide reportedly occurred more frequently in grape than in other juices. However, estimates of short-term intake were below proposed acute reference doses (53003).
Ochratoxin A is a mycotoxin that is suspected to be nephrotoxic, teratogenic, hepatotoxic and carcinogenic and has been identified in grape juice, frozen grape pulps, and red and white wine sold in Rio de Janeiro, Brazil. However, the highest levels identified in grape products were lower than the established virtually safe dose of 5 ng/kg of body weight daily (53010,53004). Ochratoxin A has also been identified in red, but not white, grape juice marketed in Switzerland, Canada, and the U.S. (53292,53020).

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General ...Orally, stinging nettle seems to be generally well tolerated.
Most Common Adverse Effects:
Orally: Constipation, diarrhea.
Topically: Contact with the raw plant causes itching, rash, and stinging.

Dermatologic ...Topically, fresh stinging nettle leaves and stalk can cause localized rash, itching, and stinging (12490,76399,76412,76414,76417,76428,76448,96746). Usually, short exposure to stinging nettle results in a transient urticarial reaction and a stinging sensation which may persist for more than 12 hours (76399,76414,76417,96746). In one report, a patient placed a fresh stinging nettle leaf on the tongue to suck out the sap of the leaf. Severe tongue edema, pain, and urticaria developed within 5 minutes. Symptoms continued for several hours after the leaf was removed (15197). In another case report, a young couple intoxicated with methamphetamine fell and laid in a stinging nettle bush for 20 minutes, after which urticaria and pain continued for 2-3 weeks, and a heightened sensitivity to cold persisted for several months (96746).

Endocrine ...A case of gynecomastia has been reported for a 33-year-old male who consumed stinging nettle tea 2 cups daily for one month prior to symptom onset. The condition subsided one month after discontinuing stinging nettle tea (76410).
There have been two cases of galactorrhea associated with the consumption of stinging nettle for one month (76410,108902). In one case, a 33-year-old female consuming stinging nettle tea showed high levels of estradiol and low levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH). The levels of these hormones normalized 6 weeks after discontinuing stinging nettle tea (76410). In the other case report describing a 30-year-old female self-treating with stinging nettle 500 mg daily, hormone levels were not reported; however, a mammogram showed scattered areas of fibroglandular density and benign-appearing calcifications. This patient had complete resolution of symptoms 1 week after discontinuation of stinging nettle (108902).

Gastrointestinal ...Orally, stinging nettle root can cause gastrointestinal complaints, including diarrhea and constipation (1,7,11230). Stinging nettle above ground parts may cause mild gastrointestinal discomfort when taken on an empty stomach (7035). Stinging nettle juice may cause diarrhea (1). One patient taking a combination product containing stinging nettle root extract and pygeum bark extract (Prostatonin, Pharmaton) experienced continual gastrointestinal pain and hyperperistalsis. It is not clear if this effect was due to stinging nettle or pygeum (70230).

Genitourinary ...There is a case report of decreased ejaculatory volume associated with an herbal blend product containing stinging nettle root extract, saw palmetto extract, pumpkin seed oil extract, lemon bioflavonoid extract, and beta-carotene (5093). It is unclear if this was due to stinging nettle, other ingredients, or the combination.

Hepatic ...A case of idiosyncratic drug-induced liver disease (DILI) is reported in a 36-year-old female who presented with abdominal pain after 1 month of taking an herbal liver detox tea containing stinging nettle and other ingredients. Remarkable laboratory values included elevated liver enzymes, alkaline phosphatase, and total bilirubin. The patient received a loading dose of N-acetylcysteine and was hospitalized for 12 days (112178). However, it is unclear if the adverse effect was due to the stinging nettle, other ingredients, or the combination.

Other ...Orally, stinging nettle root can cause sweating (1,7).

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