Berberine is a plant compound used for blood sugar and cholesterol, with effects that can be close to medicines.
Calculator Official intake Study doses Best form Safety Sources
This is not an essential nutrient, so there is no official daily intake. Only study doses are shown.
These are doses tested in research, not personal advice. Some exceed the upper limit because they were short courses or given under medical care.
1,500 mg a day
A meta-analysis of 28 studies (2,313 patients) found lower fasting and after-meal glucose and HbA1c. In a pilot trial, 0.5 g three times a day worked about as well as metformin; a third of patients had passing stomach upset. Effects faded in trials longer than 3 months or above 2 g a day.
Found in barberry and goldenseal roots, not in normal foods.
It lowers blood sugar, so it can add to diabetes medicines. Talk to your doctor first.
Stomach upset is common: a third of patients in one trial had passing stomach problems.
Pregnant, breastfeeding, on medication, or managing a health condition? Check with a doctor or pharmacist before starting a supplement.
Values checked: November 12, 2026.