- What is berberine? 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 ConsumerTips™). Use the Results table to compare the amounts of berberine we found in supplements.
- What do berberine and goldenseal 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 berberine should I 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 for berberine supplements? 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.
- Safety and side effects of berberine and goldenseal: 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.