How much berberine do you need per day?

How much berberine you need per day depends on what you are using it for. For blood sugar regulation in type 2 diabetes, several studies found the best results at 1 gram per day. A meta-analysis of 28 controlled trials (over 2,300 participants) showed that berberine lowered fasting blood glucose by an average of 0.54 mmol/L compared to a control group. Doses above 2 grams per day or use lasting longer than 90 days did not appear to strengthen the effect but actually reduced it.

For reducing the recurrence of intestinal polyps after removal, a large double-blind study (891 participants) points to 0.6 grams per day, divided into two doses of 0.3 grams. This produced a risk reduction of approximately 23%. This is the best-supported dose from the available studies.

For cholesterol, the picture is less clear. A small comparative study using a combination product (berberine plus other substances) found a greater LDL reduction at 1,000 mg per day than at 500 mg, but because berberine was never given alone in that study, it is not possible to determine what berberine itself contributed. At 300 mg per day, beneficial effects on genes that regulate cholesterol were reported, but this evidence is preliminary and associative.

In the area of gut bacteria, 500 mg per day modulated their composition, but the evidence is thin and the direction of the effect is not unambiguously positive or negative.

An important safety point: if you use metformin, caution is warranted. There is a demonstrated interaction between berberine and metformin that can affect exposure to that medication. Discuss this with your doctor or pharmacist before using berberine.