Oregon grape contains berberine and side effects can result from high dosages including gastrointestinal discomfort, dyspnea, lowered blood pressure, flu-like symptoms, and cardiac damage.


– Birdsall TC, Kelly GS. — Berberine: Therapeutic potential of an alkaloid found in several medicinal plants. — Altern Med Rev 1997;2:94-103.

Berberine usage should be avoided in pregnancy, due to potential for causing uterine contractions and miscarriage, and in jaundiced neonates because of its bilirubin displacement properties.


– Birdsall TC, Kelly GS. — Berberine: Therapeutic potential of an alkaloid found in several medicinal plants. — Altern Med Rev 1997;2:94-103.

The use of the herb and other traditional Chinese medicines containing a high proportion of berberine is best avoided in jaundiced neonates and pregnant women.

– Biol Neonate 1993;63(4):201-8 — Displacement of bilirubin from albumin by berberine. — Chan E.