Blood Sugar & Cardiovascular Support. Suitable for Vegetarians/Vegans. Purity & Potency Guaranteed. Berberine is a naturally occurring plant alkaloid found in various plants, including barberry, goldenseal and Oregon grape. Many herbalists credit this unique alkaloid for the beneficial effects of many traditional tonics made from these plants. Berberine plays an important role in blood sugar (glucose) metabolism and cardiovascular health. Berberine helps maintain blood sugar and total cholesterol levels already within the normal range.