Goldenseal can inhibit CYP2D6 and CYP3A4, enzymes involved in the metabolism of many medicines. Human studies also found a clinically meaningful reduction in metformin exposure, making medication review essential before use.

Contraindicated / High risk. Use only under qualified healthcare supervision.

Contraindications

Pregnancy or breastfeeding
Use in infants or newborns
Use with prescription medicine without interaction review

Cautions

Goldenseal has an overall high interaction risk because it inhibits CYP2D6 and CYP3A4.
Its berberine constituent can harm newborns and may worsen jaundice.
Commercial products may be adulterated or contain little goldenseal.

Drug Interactions

Drug Class / Substrate	Mechanism	Severity	Source
Metformin	Goldenseal reduced metformin exposure by about 25 percent in healthy adults and showed a dose-dependent interaction in adults with type 2 diabetes.	Major	NCCIH Goldenseal
CYP2D6 and CYP3A4 substrate medicines	Goldenseal inhibits both major metabolic enzymes and can increase toxicity or alter drug effects across many classes.	Major	NCCIH Herb-Drug Interactions
Midazolam and other sensitive CYP3A4 substrates	Human pharmacokinetic research confirms an interaction consistent with intestinal CYP3A4 inhibition.	Major	NCCIH Goldenseal

Pregnancy

Not recommended during pregnancy. Consult a qualified healthcare provider before any use.

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.