Oregon Grape Side Effects and Warnings

Safety Issues

Oregon grape appears to be safe when used as directed. In the large open study described above, only 5 of the 443 participants reported side effects of burning, redness, and itching. ¹ However, because Oregon grape contains berberine, which has been reported to cause uterine contractions and to increase levels of bilirubin, oral consumption of Oregon grape should be avoided by pregnant women. ² Safety in young children, nursing women, or people with severe liver or kidney disease has not been established.

There is an additional concern regarding the berberine content of Oregon grape. One study found that berberine impairs metabolism of the drug cyclosporine, thereby raising its levels. ³ This could potentially cause toxicity.