Phytogen [Discontinued] by Thorne

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if oral astragalus is beneficial for allergic rhinitis. Details: Preliminary clinical research shows that taking a specific astragalus root extract standardized to contain 40% polysaccharides (Lectranal, Milsing d.o.o.) 160 mg orally twice daily for 3-6 weeks improves symptoms such as rhinorrhea, sneezing, and itching when compared with placebo in adults with seasonal allergic rhinitis (17355).
• Amenorrhea. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One preliminary clinical study shows that taking a liquid decoction containing astragalus 30 grams, dong quai 30 grams, zizyphus 10 fruits, horny goat weed 15 grams, dodder 30 grams, and three slices of ginger, daily in two divided doses for 3 months, can increase menstrual frequency when compared to baseline in patients with amenorrhea (33050). The validity of this finding is limited by the lack of a comparator group.
• Angina. It is unclear if oral astragalus is beneficial for angina. Details: A preliminary clinical trial shows that taking astragalus 20 grams orally three times daily for 2 weeks can improve cardiac output, but not diastolic function, when compared to baseline in patients with angina (33063). The validity of these findings is limited by the lack of a comparator group.
• Anthracycline cardiotoxicity. It is unclear if intravenous astragalus is beneficial for preventing cardiotoxicity due to anthracyclines. Oral astragalus has not been evaluated for this use. Details: A large unblinded clinical study in patients with breast cancer or lymphoma receiving a chemotherapy regimen containing epirubicin shows that intravenous use of astragalus 500 mg daily for 14 days during 2 courses of chemotherapy modestly attenuates the decline in left ventricular ejection fraction (LVEF) and reduces the occurrence of cardiotoxicity when compared with standard care (110479). However, this study was conducted in China, which limits the generalizability of its results.
• Aplastic anemia. It is unclear if intravenous astragalus is beneficial for aplastic anemia. There is insufficient reliable information about the clinical effects of oral astragalus for this condition. Details: Preliminary clinical research in patients 15 years and older with chronic aplastic anemia shows that giving intravenous astragalus in combination with stanozolol 2 mg three times daily produces greater improvements in symptoms and blood cell counts than stanozolol alone. Astragalus was given as 80-120 grams daily for repeated 15-day courses at 7-10 day intervals for at least 4 months (32840).
• Asthma. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children with mild asthma shows that taking a combination of astragalus, cordyceps, Radix stemonae (Bai Bu), bulbus fritillariae cirrhosae, and Baikal skullcap orally for 6 months does not improve asthma symptoms, measures of lung function, or total steroid use when compared with placebo (32935).
• Beta-thalassemia. Although there has been interest in using oral astragalus for beta-thalassemia, there is insufficient reliable information about the clinical effects of astragalus for this condition.
• Breast cancer. Although there has been interest in using oral astragalus for breast cancer, there is insufficient reliable information about the clinical effects of astragalus for this condition.
• Cervical cancer. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of 19 clinical trials in adults with cervical cancer who are receiving chemotherapy shows that the use of Chinese herbal medicines containing astragalus increases tumor response (complete and partial responses) and Karnofsky performance score and reduces chemotherapy-associated adverse effects when compared with chemotherapy alone (107479). However, most studies included in the meta-analysis were low-quality, and all studies were conducted in China. Higher quality studies in other geographic locations are needed to confirm these findings. Additionally, it is unclear if any effects are due to astragalus, other ingredients, or the combination.
• Chemotherapy-induced anemia. Oral or intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of low-quality clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy reduces the risk of anemia by 51% when compared with chemotherapy alone (102099). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Chemotherapy-induced diarrhea. It is unclear if oral or intravenous astragalus is beneficial for chemotherapy-induced diarrhea. Details: One preliminary clinical study shows that intravenous infusion of astragalus 40 grams in 250 mL of solution, given daily for 21 days during each of four courses of chemotherapy, reduces diarrhea by 59% when compared to chemotherapy alone (32747). Additionally, a meta-analysis of low-quality clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy reduces the risk of diarrhea by 45% when compared with chemotherapy alone (102099). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Chemotherapy-induced leukopenia. Oral or intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of low-quality clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy reduces the risk of thrombocytopenia by 41% when compared with chemotherapy alone (102099). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Chemotherapy-induced nausea and vomiting (CINV). Early research suggests that intravenous astragalus seems to reduce nausea and vomiting associated with chemotherapy use. It is unclear if oral astragalus is beneficial for CINV. Details: A meta-analysis of low-quality clinical research in Chinese patients with advanced non-small cell lung cancer shows that intravenous infusion of astragalus along with platinum-based chemotherapy reduces the risk of vomiting by 38% when compared with platinum-based chemotherapy alone (100698). Another preliminary clinical study shows that intravenous infusion of astragalus 40 grams in 250 mL of solution, given daily for 21 days during each of four courses of chemotherapy, reduces nausea by 36% and vomiting by 50% when compared with chemotherapy alone (32747). Higher quality studies are needed to confirm these results. The use of astragalus in combination with other ingredients for prevention of CINV has also been investigated. A meta-analysis of low-quality clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy reduces the risk of nausea and vomiting by 44% when compared with chemotherapy alone (102099). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Chemotherapy-induced nephrotoxicity. Oral or intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of low-quality clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy does not reduce the risk of nephrotoxicity when compared with chemotherapy alone (102099). The effects of astragalus when used alone are unclear.
• Chemotherapy-related fatigue. It is unclear if intravenous astragalus is beneficial for chemotherapy-related fatigue. There is insufficient reliable information about the clinical effects of oral astragalus for this condition. Details: One clinical study in patients with advanced cancer shows that treatment with an intravenous infusion of a partially purified astragalus extract (PG2, Pharmagenesis), 500 mg three times weekly for 4 weeks during chemotherapy, improves fatigue scores after one week, but not after two and four weeks, when compared with placebo (33034).
• Chronic fatigue syndrome (CFS). Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One preliminary clinical study in adults with CFS shows that taking a 200 mL decoction containing astragalus 30 grams, kudzu 30 grams, codonopsis 15 grams, red sage 10 grams, aizoon stonecrop 15 grams, horny goat weed 10 grams, turmeric 10 grams, and calamus 10 grams, in two divided doses daily for 3 months improves fatigue symptoms when compared to baseline (32920). Another preliminary clinical study shows that taking 1.5 grams of a specific product (Myelophil, Samik Pharmaceutical Company) containing 66% of extracts of astragalus and danshen in a 1:1 ratio twice daily for 4 weeks improves fatigue severity when compared with placebo. However, taking 3 grams of the same product twice daily does not seem to have a benefit (32883). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Chronic kidney disease (CKD). It is unclear if intravenous astragalus is beneficial for CKD. There is insufficient reliable information about the clinical effects of oral astragalus for this condition. Details: A meta-analysis of preliminary clinical research in patients with CKD shows that using astragalus, usually as an injection, along with conventional treatment modestly improves creatinine clearance by 6 mL/min, serum creatinine by 0.25 mg/dL, and hemoglobin levels by 1 gram/dL when compared with conventional treatment alone (90660). However, the studies included in the meta-analysis were of low quality. Also, it is not known if astragalus reduces mortality or attenuates the progression to kidney failure.
• Cirrhosis. Intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. There is insufficient reliable information about the clinical effects of oral astragalus for this condition. Details: A meta-analysis of results from low-quality clinical studies shows that intravenous injection of a combination of astragalus and danshen for up to 90 days might decrease fibrosis when compared with control in patients with liver cirrhosis (90662). However, it is unclear if this is due to astragalus, danshen, or the combination.
• Colorectal cancer. Oral or intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of clinical trials in patients with colorectal cancer shows that oral or intravenous use of traditional Chinese medicine therapies containing astragalus and other ingredients along with conventional chemotherapy improves quality of life scores and increases the rate of tumor response by 52% when compared with chemotherapy alone (102099). It is unclear if these effects are due to astragalus, the other ingredients, or the combination.
• Congestive heart failure (CHF). It is unclear if oral or intravenous astragalus is beneficial for CHF. Details: One preliminary clinical study in adults with CHF shows that intravenous infusion of astragalus 60 grams daily for 20 days improves left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) when compared with conventional treatment (32755). However, another preliminary clinical study shows that intravenous astragalus 60 grams daily for 28 days in combination with conventional treatment for CHF does not improve LVEF, LVEDV, or left ventricular end-systolic volume when compared with conventional treatment alone (32812). Both of these studies have methodological problems. Other preliminary clinical research shows that taking oral astragalus 2.25-7.5 grams twice daily for 14-30 days in combination with conventional treatment improves cardiac function, LVEF, and walking distance when compared with conventional treatment alone (33018,33022).
• Diabetes. It is unclear if oral or intravenous astragalus is beneficial for diabetes. Details: A meta-analysis of preliminary clinical research in Chinese patients with type 2 diabetes shows that astragalus, given as a daily intravenous injection 40-80 grams or taken orally 40-60 grams daily as an aqueous decoction for up to 4 months, modestly improves fasting and postprandial blood glucose levels when compared to a control group. Oral astragalus seems to improve these outcomes slightly more than intravenous astragalus. Orally, astragalus also seems to improve fasting insulin levels and insulin resistance, although its effect on glycated hemoglobin (HbA1c) is inconsistent. The clinical studies included in this analysis were of low methodological quality and included only Chinese patients, which limits the reliability and generalizability of the results (95909). Some research has evaluated astragalus in combination with other ingredients. One preliminary clinical study in adults with previously untreated type 2 diabetes shows that taking astragalus 210 mg, goldthread 350 mg, and honeysuckle 840 mg three times daily before meals for 3 months does not improve fasting blood glucose, postprandial blood glucose, or HbA1c when compared with placebo, although glucose disposal rate is modestly improved (32925).
• Diabetic nephropathy. It is unclear if intravenous astragalus is beneficial for diabetic nephropathy. Details: Meta-analyses of small, low-quality clinical studies including over 4700 patients shows that adding intravenous astragalus to routine therapy for 2-12 weeks modestly improves blood urea nitrogen, serum creatinine, creatinine clearance, urinary protein, urinary albumin, and serum albumin when compared with routine therapy alone in patients with diabetic nephropathy (33019,102100).
• Diabetic retinopathy. It is unclear if oral astragalus is beneficial for diabetic retinopathy. Details: A meta-analysis of results from preliminary clinical research suggests that taking astragalus-containing products for up to 10 months modestly improves visual acuity and fundus manifestations when compared with control in patients with diabetic retinopathy. However, the included studies had methodological limitations, and the results were heterogeneous (90655).
• Fibromyalgia. Although there has been interest in using oral astragalus for fibromyalgia, there is insufficient reliable information about the clinical effects of astragalus for this condition.
• Gastric cancer. Oral and intravenous astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of 35 randomized, controlled trials involving 2670 patients with advanced gastric cancer shows that taking either intravenous or oral traditional Chinese medicines containing astragalus in conjunction with platinum-based chemotherapy may improve objective response rate, disease control rate, 1-year survival rate, and quality of life, and may also reduce the severity of chemotherapy-associated adverse effects, when compared with chemotherapy alone (107480). The validity of this meta-analysis is limited by potential publication bias, unclear randomization methods, and substantial heterogeneity among the included studies. Additionally, it is unclear if these effects are due to astragalus, other ingredients, or the combination.
• Hearing loss. It is unclear if intravenous astragalus is beneficial for hearing loss. Details: Preliminary clinical research shows that injecting 0.5 mL/kg of solution containing astragalus 2 grams/mL daily for 10 days improves hearing in people with sudden deafness or acute acoustic trauma when compared with a control group (33028,33033).
• Hepatitis B. Although there has been interest in using oral astragalus for hepatitis B, there is insufficient reliable information about the clinical effects of astragalus for this condition.
• HIV/AIDS. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study shows that taking a combination containing mainly Baikal skullcap root, glossy privet fruit, astragalus root, and Eupolyphaga et polyphage (Ailing granules) 20 grams twice daily for 4 months improves HIV/AIDS symptoms and CD4 cell counts (32824). However, taking a different combination containing licorice, yin chen, white mulberry, astragalus, and safflower orally for 12 weeks is associated with only a slight decline in viral load and no change in CD4 cell counts (32795). The effects of astragalus alone are unclear.
• IgA nephropathy. Although there has been interest in using intravenous astragalus for IgA nephropathy, there is insufficient reliable information about the clinical effects of oral or intravenous astragalus for this condition.
• Lung cancer. Early research suggests that oral or intravenous astragalus seems to increase the effectiveness of platinum-based chemotherapy or radiotherapy in patients with advanced non-small cell lung cancer (NSCLC). Details: One meta-analysis in patients with advanced NSCLC shows that intravenous administration of astragalus along with platinum-based chemotherapy increases the rate of one-year survival by 40% when compared with platinum-based chemotherapy alone (100698). Other meta-analyses in these patients show that use of oral or intravenous astragalus-containing herbal products appears to reduce the risk of death at six months by 42%, at one year by 33%, at two years by 27% to 33%, and at three years by 15% to 24% when compared with platinum-based chemotherapy or radiotherapy alone (15001,90656). However, most studies included in the meta-analyses were low-quality, and all studies were conducted in China. Higher quality studies in other geographic locations are needed to confirm these findings.
• Membranous nephropathy. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of 48 small, low-quality clinical studies in adults with idiopathic membranous nephropathy conducted in China shows that taking astragalus 20-90 grams per day in combination with a variety of other supplements, in addition to conventional therapy, modestly improves the rate of complete or partial renal remission when compared with conventional therapy (e.g. angiotensin-converting enzyme inhibitors, immunosuppression). Adding astragalus combinations to conventional therapy also modestly reduces proteinuria and serum creatinine (112010). However, the interpretation of these findings is limited by the heterogeneity of the included studies and variable definitions of complete and partial renal remission. Additionally, it is unclear if these effects are due to astragalus, other ingredients, or the combination.
• Menopausal symptoms. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One preliminary clinical study shows that taking Dang Gui Buxue Tang, an herbal decoction containing astragalus and dong quai extract, 3 grams daily for 6 months does not reduce the incidence of menopausal hot flashes (32857). However, another preliminary clinical study shows that taking Dang Gui Buxue Tang 3-6 grams daily for 12 weeks reduces hot flash frequency by up to 40% and night sweat frequency up to 53% when compared to baseline (90659). Each 1.5 grams of Dang gui Buxue Tang contains extract prepared from dong quai 1.5 grams and astragalus 7.5 grams (90659). Another small clinical study in females with moderate or severe menopausal symptoms shows that taking a tablet containing astragalus and Rubus coreanus extract 1000 mg twice daily for 12 weeks modestly improves symptom and quality of life scores when compared with placebo (110478). However, the validity of these findings is limited by a high rate of study participant discontinuation.
• Myocardial infarction (MI). Although there has been interest in using intravenous astragalus for MI, there is insufficient reliable information about the clinical effects of oral or intravenous astragalus for this purpose.
• Myocarditis. It is unclear if oral or injectable astragalus is beneficial for viral myocarditis. Details: A meta-analysis of 13 mostly small, low-quality clinical studies in adults and children with viral myocarditis shows that astragalus injection may improve the total effective rate and reduce markers of inflammation when compared with conventional treatment (110477). However, most studies included in the meta-analysis were low-quality, dosing was variable, and all studies were conducted in China. Higher quality studies in other geographic locations are needed to confirm these findings. Several clinical studies report improvements in cardiac enzymes, cardiac function, or viral load in peripheral leukocytes with the use of astragalus preparations, but results are inconsistent and the methodological quality of these studies is low (33084,33105,33217,33218,33220,33221,33223). Doses demonstrating benefit include intramuscular astragalus extract, equivalent to 8 grams daily for 3-4 months (33105) and intravenous astragalus extract 40 grams daily for 2 weeks (33218,33221). It is unclear if astragalus speeds recovery or reduces the risk of mortality due to myocarditis.
• Nephrotic syndrome. It is unclear if oral astragalus is beneficial for preventing infections in patients with nephrotic syndrome. Details: A meta-analysis of results from two preliminary clinical studies shows that taking astragalus 7.5-15 grams twice daily for 3-6 months reduces the risk of infection by 38% when compared to control in children with nephrotic syndrome (33036).
• Obesity. Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination of astragalus, rhubarb, turmeric, red sage root, ginger, and gallic acid concurrently with a reduced-calorie diet does not improve weight loss when compared with a reduced-calorie diet alone in adults who are overweight or obese (20347).
• Post-stroke fatigue. It is unclear if oral astragalus is beneficial for post-stroke fatigue. Details: A preliminary clinical study shows that taking astralagus extract (Sun Ten Pharmaceutical Co. Ltd.) 2.8 grams three times daily for 28 days improves fatigue and some quality of life measures such as social functioning, role functioning, and physical functioning, when compared with placebo in patients experiencing fatigue following a recent stroke (95908).
• Systemic lupus erythematosus (SLE). It is unclear if intravenous astragalus is beneficial for lupus nephritis. There is insufficient reliable information about the clinical effects of oral astragalus for this condition. Details: A preliminary clinical study in adults with lupus nephritis shows that intravenous infusions of astragalus 40 grams daily for 12 consecutive days monthly for 3 months, in combination with corticosteroids and cyclophosphamide once monthly as an intravenous drip, can improve symptoms, reduce infections, and reduce urinary protein excretion when compared to treatment with corticosteroids and cyclophosphamide alone (32838).
• Tinnitus. It is unclear if intravenous astragalus is beneficial for tinnitus. Details: Preliminary clinical research shows that injecting 0.5 mL/kg of solution containing astragalus 2 grams/mL daily for 10 days reduces tinnitus in patients with acute acoustic trauma when compared to a control group (33028).
• Upper respiratory tract infection (URTI). Although there has been interest in using oral astragalus for URTI prevention, there is insufficient reliable information about the clinical effects of astragalus for this purpose.
• Urinary Tract Infections (UTIs). Oral astragalus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-size clinical study in females aged 18-45 with uncomplicated UTIs shows that taking a supplement containing astragalus root extract 100 mg, d-mannose, citric acid, dandelion, and prebiotics as a sachet dissolved in water twice daily for 5 days improves complete resolution of UTI symptoms and clearance of bacteriuria at days 6 and 35 when compared with placebo (111757). However, it is unclear if these effects are due to astragalus, other ingredients, or the combination.
• Wound healing. Although there has been interest in using topical astragalus for wound healing, there is insufficient reliable information about the clinical effects of astragalus for this purpose. More evidence is needed to rate astragalus for these uses.

(Read more about ASTRAGALUS)

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 respiraA 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.

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There is insufficient reliable information available about the effectiveness of goldthread.

(Read more about GOLDTHREAD)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging. Although there is interest in using oral schisandra for aging, there is insufficient reliable information about the clinical effects of schisandra for this purpose.
• Asthma. Although there is interest in using oral schisandra for asthma, there is insufficient reliable information about the clinical effects of schisandra for this condition.
• Athletic performance. Although there is interest in using oral schisandra for athletic performance, there is insufficient reliable information about the clinical effects of schisandra for this purpose.
• Coronavirus disease 2019 (COVID-19). Oral schisandra has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with a history of COVID-19 infection and current symptoms of long COVID-19 shows that taking 30 mL of a specific combination product (Chisan / ADAPT-232, Swedish Herbal Institute) containing schisandra extract 300 mg, rhodiola extract 90 mg, and eleuthero extract 78 mg twice daily for 2 weeks increases exercise capacity, but does not reduce the number of days with fatigue, headache, cough, respiratory problems, or other symptoms of long COVID-19, when compared with placebo (109635).
• Cough. Although there is interest in using oral schisandra for cough, there is insufficient reliable information about the clinical effects of schisandra for this purpose.
• Diarrhea. Although there is interest in using oral schisandra for diarrhea, there is insufficient reliable information about the clinical effects of schisandra for this purpose.
• Diabetes. Although there is interest in using oral schisandra for diabetes, there is insufficient reliable information about the clinical effects of schisandra for this condition.
• Familial Mediterranean fever. Oral schisandra has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in children ages 3-15 years with familial Mediterranean fever shows that taking a combination product (ImmunoGuard, Inspired Nutritionals) containing schisandra extract 100 mg, andrographis, Siberian ginseng, and licorice reduces symptom duration, frequency, and severity when compared with placebo (12382). It is unclear if these effects are due to schisandra, other ingredients, or the combination.
• Hepatitis. Although there is interest in using oral schisandra for hepatitis, there is insufficient reliable information about the clinical effects of schisandra for this condition.
• Hypercholesterolemia. Although there is interest in using oral schisandra for hypercholesterolemia, there is insufficient reliable information about the clinical effects of schisandra for this condition.
• Menopausal symptoms. It is unclear if oral schisandra is beneficial for improving menopausal symptoms. Details: A small clinical trial in healthy patients with moderate or severe menopausal symptoms shows that taking schisandra extract (BMO-30, Biomix Inc) 784 mg in two divided doses daily for 6 weeks improves hot flushes and other menopausal symptoms when compared with placebo (96632).
• Muscle strength. It is unclear if oral schisandra is beneficial for improving muscle strength. Details: A small clinical study in healthy middle-aged females shows that taking schisandra powdered extract (Bioport Korea Inc.) 500 mg twice daily for 12 weeks seems to modestly increase quadriceps muscle strength and grip strength, but does not affect overall muscle mass, when compared with placebo (105563).
• Myopia. Although there is interest in using topical schisandra for myopia in children, there is insufficient reliable information about the clinical effects of schisandra for this condition.
• Physical performance. It is unclear if oral schisandra is beneficial for improving physical function in older adults. Details: A small clinical study in healthy adults over 50 years of age shows that taking schisandra 500 mg twice daily, 30 minutes after breakfast and dinner, for 12 months improves knee extension peak torque, but does not improve hand grip strength or body composition, when compared with placebo (105562).
• Pneumonia. Oral schisandra has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with acute, nonspecific pneumonia shows that taking 20 mL of a specific combination product (ADAPT-232 CHI San, Swedish Herbal Institute) containing schisandra berry extract 51%, rhodiola root extract 27.6%, and eleuthero root extract 24.4% twice daily for 10-15 days reduces the duration of antibiotic treatment and may improve quality of life when compared with standard treatment alone (71152). It is unclear if these effects are due to schisandra, other ingredients, or the combination.
• Stress. Oral schisandra has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in healthy, fatigued females under experimental stress suggests that taking a single, 270 mg dose of a combination product (ADAPT-232, Swedish Herbal Institute) containing schisandra, rhodiola, and Siberian ginseng improves attention, as well as cognitive task speed and accuracy, when compared with placebo (19289). It is unclear if these effects are due to schisandra, other ingredients, or the combination. More evidence is needed to rate schisandra for these uses.

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POSSIBLY SAFE ...when used orally and appropriately. Doses of astragalus up to 60 grams daily for up to 4 months have been used without reported adverse effects (32920,33038,95909). ...when used intravenously. Infusion of doses up to 80 grams daily for up to 4 months under the supervision of a medical professional have been used with apparent safety (32811,32812,32828,95909). There is insufficient reliable information available about the safety of astragalus when used topically.

PREGNANCY AND LACTATION:
There is insufficient reliable information in humans. However, astragaloside, a constituent of astragalus, has maternal and fetal toxic effects in animals (32881). Avoid using.

(Read more about ASTRAGALUS)

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.

(Read more about ECHINACEA)

There is insufficient reliable information available about the safety of goldthread when used in adults in medicinal amounts.

CHILDREN: LIKELY UNSAFE
when used orally in newborns. The berberine constituent of goldthread 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 berberine (2589). Preliminary evidence suggests that maternal intake of goldthread during the first trimester increases the risk of congenital malformations of the central nervous system (15129).

LACTATION: LIKELY UNSAFE
when used orally. Berberine and other harmful constituents can be transferred to the infant through breast milk (2589).

(Read more about GOLDTHREAD)

POSSIBLY SAFE ...when used orally and appropriately. Schisandra extract up to 1 gram daily has been used for up to 12 weeks with apparent safety (12,96632,105562,105563).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Some evidence suggests schisandra fruit is a uterine stimulant (11).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about SCHISANDRA)

CYCLOPHOSPHAMIDE Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, astragalus might interfere with cyclophosphamide therapy.  Details Evidence regarding the effect of astragalus on immunosuppression caused by cyclophosphamide is conflicting. Some animal research suggests that astragalus reverses cyclophosphamide-induced immunosuppression (3713). However, other animal research shows no effect (418).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, astragalus might interfere with immunosuppressive therapy.  Details Astragalus seems to stimulate immune function (303,10777). Theoretically, taking astragalus might decrease the effects of immunosuppressive therapy.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, astragalus might increase levels and adverse effects of lithium.  Details Animal research suggests that astragalus has diuretic properties (15103). Theoretically, due to this diuretic effect, astragalus might reduce excretion and increase levels of lithium.

(Read more about ASTRAGALUS)

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).

(Read more about ECHINACEA)

(Read more about GOLDTHREAD)

CYCLOPHOSPHAMIDE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, schisandra might increase the levels and clinical effects of cyclophosphamide.  Details In vitro research shows that schisandra increases the concentration of cyclophosphamide, likely through inhibition of cytochrome P450 3A4. After multiple doses of the schisandra constituents schisandrin A and schisantherin A, the maximum concentration of cyclophosphamide was increased by 7% and 75%, respectively, while the overall exposure to cyclophosphamide was increased by 29% and 301%, respectively (109636).

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Schisandra can increase the levels and clinical effects of cyclosporine.  Details A small observational study in children with aplastic anemia found that taking schisandra with cyclosporine increased cyclosporine trough levels by 93% without increasing the risk of adverse events. However, the dose of cyclosporine was reduced in 9% of children to maintain appropriate cyclosporine blood concentrations (109637).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, schisandra might increase the levels and clinical effects of CYP2C19 substrates.  Details In vitro research shows that schisandra inhibits CYP2C19, and animal research shows that schisandra increases the concentration of voriconazole, a CYP2C19 substrate (105566). Theoretically, schisandra may also inhibit the metabolism of other CYP2C19 substrates. 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, schisandra might decrease the levels and clinical effects of CYP2C9 substrates.  Details In vitro and animal research suggests that schisandra induces CYP2C9 enzymes (14441). This effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Schisandra can increase the levels and clinical effects of drugs metabolized by CYP3A4.  Details Most clinical and laboratory research shows that schisandra, administered either as a single dose or up to twice daily for 14 days, inhibits CYP3A4 and increases the concentration of CYP3A4 substrates such as cyclophosphamide, midazolam, tacrolimus, and talinolol (13220,17414,23717,91386,91388,91387,96631,105564,109636,109638,109639,109640,109641). Although one in vitro and animal study shows that schisandra may induce CYP3A4 metabolism (14441), this effect appears to be overpowered by schisandra's CYP3A4 inhibitory activity and has not been reported in humans.

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Schisandra can increase the levels and clinical effects of midazolam.  Details A small pharmacokinetic study in healthy adults shows that taking schisandra extract (Hezheng Pharmaceutical Co.) containing deoxyschizandrin 33.75 mg twice daily for 8 days and a single dose of midazolam 15 mg on day 8 increases the overall exposure to midazolam by about 119%, increases the peak plasma level of midazolam by 86%, and decreases midazolam clearance by about 52%. This effect has been attributed to inhibition of CYP3A4 by schisandra (91388).

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Schisandra might increase the levels and clinical effects of P-glycoprotein substrates.  Details In vitro research shows that schisandra extracts and constituents such as schisandrin B inhibit P-glycoprotein mediated efflux in intestinal cells and in P-glycoprotein over-expressing cell lines (17414,105643,105644). Additionally, a small clinical study shows that schisandra increases the peak concentration and overall exposure to talinolol, a P-glycoprotein probe substrate (91386). Theoretically, schisandra might inhibit the efflux of other P-glycoprotein substrates.

SIROLIMUS (Rapamune) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Schisandra can increase the levels and clinical effects of sirolimus.  Details A small pharmacokinetic study in healthy volunteers shows that taking 3 capsules of schisandra (Hezheng Pharmaceutical Company) containing a total of 33.75 mg deoxyschizandrin twice daily for 13 days and then taking a single dose of sirolimus 2 mg increases the overall exposure and peak level of sirolimus by two-fold. This effect is thought to be due to inhibition of cytochrome P450 3A4 by schisandra, as well as possible inhibition of the P-glycoprotein drug transporter (105643).

TACROLIMUS (Prograf) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Schisandra can increase the levels and clinical effects of tacrolimus.  Details Clinical research in healthy volunteers and transplant patients shows that taking schisandra with tacrolimus increases tacrolimus peak levels by 183% to 268%, increases overall exposure to tacrolimus by 126% to 343%, and decreases tacrolimus clearance by 48% to 73%. This effect is thought to be due to inhibition of CYP3A4 by schisandra, and possibly also inhibition of the P-glycoprotein drug transporter. It may also be related to the inhibition of CYP3A5 in people who are CYP3A5 expressors. Small clinical studies show that schisandra increases tacrolimus levels in both expressors and non-expressors of CYP3A5 (15570,17414,91387,96631,105623,109639,109641). However, some clinical and observational research shows that schisandra increases tacrolimus levels to a greater degree in CYP3A5 expressors when compared with CYP3A5 non-expressors (109638,109640). Animal research suggests that the greatest increase in tacrolimus levels occurs when schisandra is taken either concomitantly or up to 2 hours before tacrolimus (105564).

TALINOLOL Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Schisandra can increase the levels and clinical effects of talinolol.  Details A small pharmacokinetic study in healthy volunteers shows that taking schisandra extract 300 mg twice daily for 14 days with a single dose of talinolol 100 mg on day 14 increases the peak talinolol level by 51% and the overall exposure to talinolol by 47%. This effect is thought to be due to the possible inhibition of cytochrome P450 3A4 and P-glycoprotein by schisandra (91386). tly.

VORICONAZOLE (Vfend) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, schisandra might increase the levels and clinical effects of voriconazole.  Details Animal research shows that oral schisandra given daily for 1 or 14 days increases levels of intravenously administered voriconazole, a cytochrome P450 (CYP) 2C19 substrate. This effect is thought to be due to inhibition of CYP2C19 by schisandra (105566). However, this interaction has not been reported in humans.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, schisandra might decrease the levels and clinical effects of warfarin.  Details Animal research suggests that oral schisandra extract, given daily for 6 days, reduces levels of intravenously administered warfarin. This effect might be due to the induction of cytochrome P450 (CYP) 2C9 metabolism by schisandra (14441). However, this interaction has not been reported in humans.

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General ...Orally and intravenously, astragalus root seems to be well tolerated. Topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.
Serious Adverse Effects (Rare):
Orally: A case report raises concerns about liver and kidney cysts with astragalus use.

Cardiovascular ...Orally, astragalus has reportedly been associated with lacunar angina in one clinical trial. However, this may not have been caused by astragalus (17355). In addition, rapid intravenous administration of astragalus has resulted in temporary palpitations (32812).

Dermatologic ...Intravenously, astragalus may cause rash, eczema, and pruritus (33034).

Gastrointestinal ...Orally, astragalus has reportedly been associated with enterocolitis and nausea in one clinical trial. However, these effects may not have been caused by astragalus (17355).

Genitourinary ...Orally, astragalus has reportedly been associated with vulvitis in one clinical trial. However, this effect may not have been caused by astragalus (17355).

Hepatic ...A case of high serum CA19-9 levels and small liver and kidney cysts has been reported for a 38-year-old woman who drank astragalus tea daily for one month. Levels returned to normal after one month, and cysts disappeared after ten months. Both symptoms returned following a resumption of astragalus use. The authors state that astragalus was the likely cause given the temporal relationship (90658).

Neurologic/CNS ...Rapid intravenous administration of astragalus has resulted in temporary dizziness (32812).

Pulmonary/Respiratory ...Orally, astragalus has reportedly been associated with rhinosinusitis and pharyngitis in one clinical trial. However, these effects may not have been caused by astragalus (17355).

Renal ...A case of high serum CA19-9 levels and small liver and kidney cysts has been reported for a 38-year-old woman who drank astragalus tea daily for one month. Levels returned to normal after one month, and cysts disappeared after ten months. Both symptoms returned following a resumption of astragalus use. The authors state that astragalus was the likely cause given the temporal relationship (90658).

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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 ...No adverse effects have been reported in adults. However, a thorough evaluation of safety outcomes has not been conducted.

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General ...Orally, schisandra seems to be generally well tolerated.
Most Common Adverse Effects:
Orally: Decreased appetite, heartburn, stomach upset, and urticaria.

Dermatologic ...Orally, schisandra can cause urticaria in some patients (11).

Gastrointestinal ...Orally, schisandra can cause heartburn, decreased appetite, and stomach upset (11).

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