Although berberine appears to be generally safe, more long-term safety research is needed. Supplementation with berberine (especially in doses above 300 mg/day) has been reported to cause gastrointestinal side effects in some people, including diarrhea, constipation, flatulence, and stomach pain.[1] Due to its ability to reduce blood sugar, berberine may increase the risk for hypoglycemia in high doses. Additionally, berberine inhibits several enzymes involved in drug metabolism, so there’s a risk of serious drug interactions when taken alongside other medications or supplements.[2]
What are berberine’s main drawbacks?
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•Last Updated: May 16, 2025
Berberine may cause gastrointestinal side effects such as diarrhea and stomach pain, especially at doses above 300 mg per day, and there is a risk of hypoglycemia and serious drug interactions due to its effects on blood sugar and drug metabolism. More long-term safety research is needed to fully understand its risks.