Berberine and Goldenseal Supplements Review
Initial Posting: 12/10/17 Last update: 2/4/2020
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What It Is:
- What is it? Berberine is a yellow-colored compound found in goldenseal root. As a supplement, it is typically sold in the form of berberine HCl (which is 90% berberine) in capsules or tablets containing hundreds of milligrams. Goldenseal root powder or extract supplements generally provide less than 30 mg of berberine per serving (See What It Is and What to Consider When Buying and Using). Use the Results table to compare the amounts of berberine we found in supplements.
- What does it do? Berberine appears to be effective in reducing blood sugar levels in people with type 2 diabetes or metabolic syndrome, and improvements in cholesterol levels and even body composition have been noted, although higher quality studies are needed to confirm these effects. Preliminary evidence suggests that berberine may be of benefit with certain arrhythmias and congestive heart failure. There is insufficient evidence to support the use of goldenseal root powder or extract in treating or preventing any condition (See What It Does).
- How much to take? Berberine is typically taken as 500 mg of its hydrochloride or sulfate forms two to three times daily. There is no established dose for goldenseal (See Dosage).
- Best choice? Be careful! Three-quarters of the goldenseal supplements selected for testing in this Review failed to pass testing — one contained no detectable berberine! Berberine supplements fared better, but one contained only 78% of the amount it listed and it was not properly labeled (See What CL Found). Among products that were Approved, see our Top Picks to find those that provide berberine at much lower cost than others.
- Cautions: Berberine can increase bilirubin levels and should not be taken by women who are pregnant or nursing or by young children. It may affect blood sugar levels and blood pressure. It can interfere with the activity of many drugs. Because it contains berberine, goldenseal carries the same cautions. For more details, see Concerns and Cautions.
Berberine is a bright yellow alkaloid compound found in plants such as barberry, Oregon grape and goldenseal. Although it exists in the "free form" in plants, berberine in supplements is typically chemically stabilized as either berberine hydrochloride or berberine sulfate.
Goldenseal root naturally contains a small amount of berberine (25 mg or more per 1,000 mg of root powder), which gives the root (and the base of its stem) its golden yellow hue (although not as yellow as berberine extract).
What It Does:
Although traditionally used as an antibiotic, berberine is currently promoted for a range of other uses, mostly focusing on metabolic diseases.
Several studies suggest that berberine may lower blood sugar and cholesterol, particularly in people with type 2 diabetes. In a study of 116 men and women with type 2 diabetes and elevated levels of cholesterol and/or triglycerides, those who took 500 mg of berberine (apparently as berberine sulfate) twice daily for 3 months had significantly greater improvements in fasting glucose, glucose levels after eating, and HbA1c levels (a measure of glucose levels over a period of time) than those who took a placebo. They also had greater improvements in levels of total cholesterol, "bad" LDL cholesterol, and triglycerides. (Zhang, J Clin Endocrinol Metab 2008). A small, 3-month study in men and women newly diagnosed with type 2 diabetes found that 500 mg of berberine HCl taken before meals 2 to 3 times daily was as effective as 500 mg of the diabetes drug metformin (also taken 2-3 times daily before meals) for lowering fasting glucose and glucose levels after eating, as well as HbA1c. In this study, berberine was also found to significantly reduce total and LDL cholesterol and triglyceride levels (Yin, Metabolism 2008).
A small study found that men and women with metabolic syndrome who took 500 mg of berberine hydrochloride 3 times daily with meals had significant decreases in blood sugar and insulin levels, as well as body mass index (BMI), and in women, waist circumference -- while those who took a placebo had no significant changes. Triglyceride levels and systolic blood pressure also decreased significantly among those who took berberine; cholesterol levels were not measured (Perez-Rubio, Metab Syndr Relat Discord 2013).
In a review of 14 clinical studies, researchers concluded that berberine appears to be beneficial for reducing blood sugar, although larger, high-quality studies are needed to confirm this (Dong, Evid Based Complement Alternat Med 2012).The most common side effects reported in the studies were gastrointestinal symptoms, such as diarrhea, constipation, gas and abdominal pain, but no serious adverse reactions were reported.
A combination of berberine (500 mg) and red yeast rice (providing 3 mg of lovastatin), taken once daily, was found to further reduce LDL and total cholesterol levels in a 47-year-old woman with statin intolerance and familial hypercholesterolemia who was already being treated with the non-statin cholesterol-lowering medications evolocumab and ezetimibe. The prescription medications lowered her LDL and total cholesterol levels from 363 mg/dL and 445 mg/dL, respectively, to 115 mg/dL and 185 mg/dL, and adding the berberine and red yeast rice further lowered her levels to 68 mg/dL and 143 mg/dL, respectively (Parra-Virto, Clin Investig Arterioscler 2018).
Preliminary research suggests that berberine can help reduce premature ventricular contractions in people with ventricular tachyarrhythmia and strengthen heart contractions in people with congestive heart failure (Xia, Chronic Dis Transl Med 2015).
A 2-year, controlled trial in China of over 800 people aged 18-75 with a history of removal of colorectal adenomas found that 300 mg of berberine (as berberine HCL) taken twice daily modestly reduced the risk of developing additional precancerous polyps to 36% in the berberine group versus 47% in the placebo group. Even after adjusting for a greater proportion of the placebo group having advanced colorectal adenoma at baseline (a strong risk factor for recurrent adenoma), the risk reduction with berberine was still statistically significant (Chen, Lancet Gastroenterol Hepatol, 2020).
There is insufficient evidence to support goldenseal's use in the prevention or treatment of any disease.
Due to the ability of berberine to inhibit or kill microorganisms in laboratory experiments, goldenseal root has been suggested as topical or oral antibiotic. However, the efficacy of these applications has not been demonstrated.
There is only weak evidence that goldenseal may be helpful lowering cholesterol and improving blood sugar control, as well as helping with arrhythmias, congestive heart failure, high blood pressure, dyspepsia, and irritable bowel syndrome.
Goldenseal is sometimes combined with Echinacea and taken as an immune booster or antibiotic for the prevention and treatment of colds, but there is no credible evidence to support goldenseal's use in these applications.
Although a myth has been perpetuated that goldenseal can block a positive drug screen, there is no evidence to support this.
See the Goldenseal article in our encyclopedia for more details about the clinical use of goldenseal root.