Herb & supplement monograph

Goldenseal Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Goldenseal interacts with medications. The heart of this page is the interaction list — every drug Goldenseal is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Goldenseal is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Goldenseal Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, Goldenseal drug interactions carry a moderate overall risk, mainly because goldenseal can slow how the body clears many common medications. Nearly all listed interactions are rated moderate, and unlike many herbs, some of goldenseal's effects have been confirmed in human studies.

Interactions deserving the most attention

The best-documented concern is that goldenseal blocks two liver enzymes the body uses to process a wide range of drugs, so medications cleared by CYP3A4 or CYP2D6 may reach higher levels than intended. A related concern involves the transplant drug tacrolimus, where a case report tied a goldenseal constituent to a sharp rise in blood levels of this narrow-margin medicine. Theoretical effects on blood thinners, diabetes drugs, and blood pressure medicines are less proven but deserve care because small changes with these medicines can matter.

What the rest of the list means

The long list of interacting medications does not mean every combination is harmful. Most entries stem from goldenseal's possible effects on the enzymes and transporters that process medications, based largely on lab or animal research. In fact, some predicted effects, such as a meaningful change in digoxin handling, did not prove clinically significant when tested in people.

Check your medications against Goldenseal

Based on HelloPharmacist’s Goldenseal interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Goldenseal

1238 medications have a known interaction with Goldenseal, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Goldenseal using our pharmacist-reviewed interaction data.

AI summaries are generated from our Goldenseal interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Goldenseal combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Goldenseal affects

Every type of medication (drug category) Goldenseal is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 16 drug categories Goldenseal interacts with

Anticoagulant/antiplatelet DrugsAntidiabetes DrugsAntihypertensive DrugsCns DepressantsCytochrome P450 2c9 (cyp2c9) SubstratesCytochrome P450 2d6 (cyp2d6) SubstratesCytochrome P450 2e1 (cyp2e1) SubstratesCytochrome P450 3a4 (cyp3a4) SubstratesDextromethorphan (robitussin Dm, Others)Digoxin (lanoxin)Losartan (cozaar)Metformin (glucophage)P-glycoprotein SubstratesPentobarbital (nembutal)Tacrolimus (prograf)Oseltamivir (tamiflu)

Anticoagulant/Antiplatelet Drugs

Theoretically, goldenseal might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.
Goldenseal contains berberine. In vitro and animal research shows that berberine can inhibit platelet aggregation. However, this effect has not been reported in humans.

Likelihood Possible Evidence D

Antidiabetes Drugs

Theoretically, goldenseal might increase the risk of hypoglycemia when used with antidiabetes drugs.
Goldenseal contains berberine. Clinical research shows that berberine can lower blood glucose levels. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D

Antihypertensive Drugs

Theoretically, goldenseal might increase the risk of hypotension when taken with antihypertensive drugs.
Goldenseal contains berberine. Animal research shows that berberine can have hypotensive effects. Also, an analysis of clinical research shows that taking berberine in combination with amlodipine can lower systolic and diastolic blood pressure when compared with amlodipine alone. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D

Cns Depressants

Theoretically, goldenseal might increase the sedative effects of CNS depressants.
Goldenseal contains berberine. Animal research shows that berberine can have sedative effects. However, this effect has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2C9.
In vitro research shows that goldenseal root extract can modestly inhibit CYP2C9. This effect may be due to its alkaloid constituents, hydrastine and berberine. However, this effect has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2D6 (Cyp2D6) Substrates

Goldenseal might increase serum levels of drugs metabolized by CYP2D6.
Clinical and in vitro research shows that goldenseal can significantly inhibit CYP2D6 enzymes, potentially increasing levels of drugs metabolized by CYP2D6.

Likelihood Probable Evidence B

Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2E1.
In vitro research shows that goldenseal root extract can inhibit the activity of CYP2E1. However, this effect has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Goldenseal might increase serum levels of drugs metabolized by CYP3A4.
Most clinical and in vitro research shows that goldenseal inhibits CYP3A4 enzyme activity and increases serum levels of CYP3A4 substrates, such as midazolam. However, in one small clinical study, goldenseal did not affect the levels of indinavir, a CYP3A4 substrate, in healthy volunteers. This is likely due to the fact that indinavir has a high oral bioavailability, making it an inadequate probe for CYP3A4 interactions and/or that it is primarily metabolized by hepatic CYP3A, while goldenseal has more potential to inhibit intestinal CYP3A enzyme activity. Both goldenseal extract and its isolated constituents berberine and hydrastine inhibit CYP3A, with hydrastine possibly having more inhibitory potential than berberine.

Likelihood Possible Evidence B

Dextromethorphan (Robitussin Dm, Others)

Theoretically, goldenseal might increase serum levels of dextromethorphan.
Goldenseal contains berberine. A small clinical study shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan.

Likelihood Possible Evidence D

Digoxin (Lanoxin)

Goldenseal might increase serum levels of digoxin, although this effect is unlikely to be clinically significant.
Clinical research shows that goldenseal modestly increases digoxin peak levels by about 14% in healthy volunteers. However, goldenseal does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC). This suggests that goldenseal does not cause a clinically significant interaction with digoxin. Digoxin is a P-glycoprotein substrate. Some evidence suggests that goldenseal constituents might affect P-glycoprotein; however, it is unclear whether these constituents inhibit or induce P-glycoprotein.

Likelihood Probable Evidence B

Losartan (Cozaar)

Theoretically, goldenseal might decrease the conversion of losartan to its active form.
Goldenseal contains berberine. A small clinical study shows that berberine inhibits cytochrome P450 2C9 (CYP2C9) activity and reduces the metabolism of losartan. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D

Metformin (Glucophage)

Theoretically, goldenseal might reduce blood levels of metformin.
In vitro research shows that goldenseal extract decreases the bioavailability of metformin, likely by interfering with transport, intestinal permeability, or other processes involved in metformin absorption. It is unclear which, if any, of metformin's transporters are inhibited by goldenseal. Goldenseal does not appear to alter the clearance or half-life of metformin.

Likelihood Possible Evidence D

P-Glycoprotein Substrates

Theoretically, goldenseal might increase or decrease serum levels of P-glycoprotein (P-gp) substrates.
There is conflicting evidence about the effect of goldenseal on P-gp. In vitro research suggests that berberine, a constituent of goldenseal, modestly inhibits P-gp efflux. Other evidence suggests that berberine induces P-gp. In healthy volunteers, goldenseal modestly increases peak levels of the P-gp substrate digoxin by about 14%. However, it does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC). This suggests that goldenseal is not a potent inhibitor of P-gp-mediated drug efflux. Until more is known, goldenseal should be used cautiously with P-gp substrates.

Likelihood Probable Evidence B

Pentobarbital (Nembutal)

Theoretically, goldenseal might increase the sedative effects of pentobarbital.
Animal research shows that berberine, a constituent of goldenseal, can prolong pentobarbital-induced sleeping time. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D

Tacrolimus (Prograf)

Theoretically, goldenseal might increase serum levels of tacrolimus.
Goldenseal contains berberine. In a 16-year-old patient with idiopathic nephrotic syndrome who was being treated with tacrolimus 6.5 mg twice daily, intake of berberine 200 mg three times daily increased the blood concentration of tacrolimus from 8 to 22 ng/mL. Following a reduction of tacrolimus dosing to 3 mg daily, blood levels of tacrolimus decreased to 12 ng/mL.

Likelihood Possible Evidence D

Oseltamivir (Tamiflu)

Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.
In vitro evidence suggests that goldenseal reduces the formation of the active compound from the prodrug oseltamivir. The mechanism of action and clinical relevance is unclear.

Likelihood Possible Evidence D

Monograph

Goldenseal: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Goldenseal is a popular North American herb that contains berberine, a compound studied for antimicrobial effects. However, strong human evidence for its many traditional uses is largely lacking, and it should be avoided during pregnancy and breastfeeding. Talk to a pharmacist or doctor before using it.

Scientific name: Hydrastis canadensis
Family: Ranunculaceae
Part used: Root and rhizome (underground stem)
Common forms: Capsules, tablets, dried root, liquid extracts, tinctures, teas, and topical preparations

People commonly use it for

Digestive upset and diarrhea
Colds and respiratory infections
Sore throat and mouth sores
Skin and eye irritation (topical/traditional)
Antimicrobial support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally used short-term by healthy adults, but human safety data are limited.

PregnancyLikely Unsafe

When used orally. Berberine is thought to cross the placenta and may cause harm to the fetus. Kernicterus has developed in newborn infants exposed to...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

LIKELY UNSAFE when used orally. Berberine and other harmful constituents can be transferred to the infant through breast milk. Use during lactation ca...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Goldenseal (Hydrastis canadensis) is a small perennial herb in the buttercup family. It is native to the woodlands of the northeastern and midwestern United States and parts of Canada. The plant has heart-shaped leaves, small flowers, and a bright yellow root that gives it its name.

The root and rhizome are the parts used in supplements. Native American peoples traditionally used goldenseal for digestive complaints, skin problems, and irritated eyes. Today people take it as capsules, tinctures, teas, and topical products, often hoping to fight infections, ease cold symptoms, or settle the stomach.

Because of heavy harvesting in the wild, goldenseal is considered a threatened plant in many areas, and much of what is sold is now cultivated.

How it works

Goldenseal contains several plant alkaloids. The best-studied are berberine and hydrastine. Berberine is the compound most often credited for goldenseal's possible effects.

In laboratory studies, berberine appears to interfere with the growth of certain microbes and may affect how cells handle sugar and inflammation. Some research suggests it can interact with surfaces of bacteria and affect their function.

It is important to know that much of this research was done in test tubes or animals, often using purified berberine rather than whole goldenseal. The amount of berberine your body actually absorbs from goldenseal taken by mouth tends to be low, so lab results may not predict real benefits in people.

Effectiveness

Does Goldenseal work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 22 uses evaluated

1 Leans ineffective 21 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Ineffective Urine drug tests