Goldenseal (Hydrastis canadensis): Uses, Evidence and Safety

Safety first: goldenseal should not be used in pregnancy or while breastfeeding, and should not be given to infants. NCCIH (US, February 2025) says the berberine in goldenseal can be harmful to newborns. [1] The US LactMed database explains the concern: berberine can displace bilirubin from serum albumin, and bilirubin can build up in an infant's brain and cause brain damage, although how much berberine passes from mother to infant is unknown. [2] Goldenseal can also change how the body handles several medicines, including metformin (see Safety below).

What goldenseal is

Goldenseal is a plant native to the northeastern United States and southeastern Canada, with a bright yellow rhizome (underground stem). [1] GBIF accepts Hydrastis canadensis L., family Ranunculaceae. [3] The root contains berberine and other isoquinoline alkaloids. [2] NCCIH also lists "yellow root" and "goldenroot" as common names. [1] This page gives no foraging or plant-identification help.

Traditional use

This is tradition, not proof. NCCIH says Native Americans historically used goldenseal for conditions such as digestive disorders, wounds, skin and eye conditions, and cancer. [1] LactMed describes goldenseal as traditionally used as an anti-infective, both inside the body and on the skin, and notes that high-quality studies of its efficacy and safety are lacking. [2] The sources do not name particular nations or practices, so we do not.

What research shows

NCCIH says there is not enough evidence to determine whether goldenseal is useful for any health condition, and no rigorous studies have evaluated its effects on health conditions in people. [1] It is promoted as a dietary supplement for the common cold and other upper respiratory tract infections, hay fever, diarrhea, constipation and other conditions. [1]

For berberine as its own supplement, see Berberine; its results should not be read as results for goldenseal.

Safety

• Medicines: NCCIH describes a study in which levels of metformin, the most commonly prescribed diabetes medicine, fell about 25 percent in healthy adults given goldenseal extract plus metformin, enough to potentially hinder glucose control in type 2 diabetes. [1] A 2021 trial in 16 healthy volunteers found goldenseal raised blood levels of midazolam (a probe for the CYP3A liver enzyme) and lowered metformin exposure by about a quarter. [4] Its authors state that goldenseal can precipitate clinical drug interactions by inhibiting the CYP3A and CYP2D6 liver enzymes, so other medicines cleared that way may also be affected. [4] A later 2025 crossover study in adults with type 2 diabetes found no clinically meaningful change overall, but metformin exposure fell about 20% at low metformin doses and 0% at high doses. The authors suggested clinicians may caution patients about combining them. [5] Ask a pharmacist, and read How Interactions Work and Interactions by Drug Class. Never change a prescribed medicine without the prescriber or pharmacist.
• Pregnancy, breastfeeding, newborns: see the warning at the top and Pregnancy and Breastfeeding.
• Length of use: NCCIH says the safety of taking goldenseal for longer periods is uncertain. [1]
• Liver and kidney, bleeding, surgery, allergy, children, older adults: not described in the sources we read. Tell the surgical team about any herbal product: Supplements Before Surgery.
• Mislabeling: NCCIH reports some commercial goldenseal products contain other herbs or ingredients not on the label, in addition to or instead of goldenseal. [1] See Quality Testing and Certifications.

Conservation

NCCIH says wild goldenseal has been overharvested and is available in limited amounts, and that the plant is grown commercially but is expensive to cultivate. [1] The sources we read do not describe legal protections, so we do not state any.

We give no amounts. A clinician or pharmacist decides what suits a person. See also Cat's Claw and Colds, Flu and Respiratory Infections.