Berberine Interactions

Berberine has potent glucose-lowering activity comparable to metformin and also inhibits CYP2C9, the enzyme responsible for clearing glipizide. The pharmacodynamic stacking plus pharmacokinetic interaction can substantially raise glipizide exposure and produce severe, prolonged hypoglycemia.

Rosuvastatin is taken into liver cells by the OATP1B1 transporter, and berberine has been shown to upregulate OATP1B1 in hepatocyte studies, increasing hepatic uptake of rosuvastatin. The clinical net effect (more LDL lowering vs. higher muscle/liver risk) is not well established in humans.

Simvastatin is extensively metabolized by CYP3A4, and berberine inhibits CYP3A4 in vitro, which can raise simvastatin levels and increase the risk of myopathy and rhabdomyolysis. The interaction is bidirectional in some models (induction is also possible), making net effect unpredictable.

Berberine inhibits CYP3A4 in vitro and can raise plasma levels of CYP3A4 substrates, including atorvastatin, which may increase the risk of muscle pain, liver enzyme elevation, and rhabdomyolysis. The interaction direction is complex — some animal data also show induction — but co-use is unpredictable.