The bioactive substance berberine comes from the plant genus Berberis: it is present in the roots, trunk, bark and also in the berries. The barberry is one of the best-known plants in this family. This shrub is native to Eurasia. Berberine is found in the following plants: European [[Barberry]], [[Goldenseal]], [[Goldthread]], [[Oregon Grape]], [[Bloodroot]], [[Yellowroot]], [[Phellodendron]] and , [[Tree Turmeric]], Tinospora cordifolia, Argemone mexicana (prickly poppy) and Eschscholzia californica (Californian poppy).
==Special Precautions of Berberine==
*Berberine can increase the amount of bilirubin in newborns. Bilirubin is a chemical released by the liver. Too much bilirubin can lead to permanent brain damage in newborns, especially in newborns born too early.