Goldenseal, an endangered US plant, is related to the buttercup (Hydrastis canadensis). Its active components are hydrastine and berberine, which have antiseptic activity. Goldenseal is available in liquid, tablet, and capsule forms standardized to the active components.
(See also Overview of Dietary Supplements.)
Efficacy of goldenseal alone as a cold remedy has not been supported (1). In 2 relatively well-designed but small studies, berberine, the major alkaline constituent isolated from goldenseal, reduced diarrhea (2-3). Berberine has also reduced symptoms in diarrhea-predominant irritable bowel syndrome (4). There are few, if any, recent, large, randomized, blinded clinical trials of goldenseal extract.
Emerging evidence shows that in diabetic patients, berberine can decrease fasting and postprandial glucose and hemoglobin A1C; a 2015 meta-analysis found that these levels were lower using berberine than with lifestyle or placebo and were also lower when berberine was combined with oral antidiabetic drugs than with antidiabetic drugs alone (5).
Goldenseal can have many adverse effects, including nausea, anxiety, dyspepsia, uterine contractions, jaundice in neonates, and worsening of hypertension. If taken in large amounts, goldenseal can cause seizures and respiratory failure and may affect contraction of the heart. Women who are pregnant or breastfeeding, neonates, and people who have seizure disorders or problems with blood clotting should not take goldenseal. A recent in vitro study of the active ingredients of goldenseal, specifically berberine, indicates an increased risk of DNA damage leading to tumorigenic effects (6).
Goldenseal may interact with warfarin, and berberine may enhance the anticoagulant effect of heparin. In addition, berberine inhibits CYP 450 isoenzymes and may increase serum concentrations of drugs such as midazolam, omeprazole, dextromethorphan, losartan, and caffeine (7).
Rehman J, Dillow JM, Carter SM, et al: Increased production of antigen-specific immunoglobulins G and M following in vivo treatment with the medicinal plants Echinacea angustifolia and Hydrastis canadensis. Immunol Lett 68(2-3):391-395, 1999. doi: 10.1016/S0165-2478(99)00085-1.
Khin-Maung-U, Myo-Khin, Nyunt-Nyunt-Wai, et al: Clinical trial of berberine in acute watery diarrhoea. Br Med J (Clin Res Ed) 291(6509):1601-1605, 1985.
Rabbani GH, Butler T, Knight J, et al: Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae. J Infect Dis 155(5):979-984, 1987.
Chen C, Tao C, Liu Z, et al: A randomized clinical trial of berberine hydrochloride in patients with diarrhea-predominant irritable bowel syndrome. Phytother Res 29(11):1822-7, 2015. doi: 10.1002/ptr.5475..
Lan J, Zhao Y, Dong F, et al: Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia, and hypertension. J Ethnopharmacol 161:69-81, 2015. doi: 10.1016/j.jep.2014.09.049.
Chen S, Wan L, Couch L, et al: Mechanism study of goldenseal-associated DNA damage. Toxicol Lett 221(1):64-72, 2013. doi: 10.1016/j.toxlet.2013.05.641.
. Guo Y, Chen Y, Tan ZR, Klaassen CD, Zhou HH: Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 68(2):213‐217, 2012. doi:10.1007/s00228-011-1108-2.
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Institutes of Health (NIH), National Center for Complementary and Integrative Health: General information on the use of goldenseal as a dietary supplement