Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what European Barberry 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

Check European Barberry against your medication

Add one medication

✓ Supplement

European Barberry

1 Your medication

Start typing any prescription or over-the-counter drug name.

Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

European Barberry Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant European Barberry drug interaction appears low for most people. None of the listed interactions are rated major, and nearly all rest on lab or animal findings rather than proven effects in people.

Interactions deserving the most attention

The best-documented concern involves diabetes medications, since early human research shows European barberry juice can lower fasting blood sugar in people already taking these drugs, which could add up to low blood sugar. Cyclosporine also deserves care, because a barberry constituent may slow how the body clears this transplant medicine and raise its levels. There is also animal and human research suggesting barberry can lower blood pressure, so people on blood pressure medications may notice an added effect.

What the rest of the list means

The long list of interacting medications mostly reflects theory rather than proven harm. Barberry contains berberine, which may affect an enzyme the body uses to clear many medications, so hundreds of drugs get flagged automatically. For most of these combinations, no meaningful problem has actually been shown in people.

Check your medications against European Barberry

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

Interaction report

Drugs that interact with European Barberry

1212 medications have a known interaction with European Barberry, 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 European Barberry using our pharmacist-reviewed interaction data.

AI summaries are generated from our European Barberry 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 European Barberry 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 European Barberry affects

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

All 8 drug categories European Barberry interacts with

Anticholinergic DrugsAnticoagulant/antiplatelet DrugsAntidiabetes DrugsAntihypertensive DrugsCholinergic DrugsCns DepressantsCyclosporine (neoral, Sandimmune)Cytochrome P450 3a4 (cyp3a4) Substrates

Anticholinergic Drugs

Theoretically, taking European barberry with anticholinergic drugs might cause additive effects.
In vitro evidence suggests that European barberry might have anticholinergic properties.

Likelihood Possible Evidence D

Anticoagulant/Antiplatelet Drugs

Theoretically, European barberry may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro and animal evidence suggest that berberine, a constituent of European barberry, might inhibit platelet aggregation. Theoretically, European barberry might have a similar effect.

Likelihood Possible Evidence D

Antidiabetes Drugs

Theoretically, taking European barberry with antidiabetes drugs might increase the risk of hypoglycemia.
Preliminary clinical evidence suggests that European barberry juice reduces fasting glucose levels in patients with type 2 diabetes who are also taking antidiabetes drugs. Additionally, some animal studies show that berberine, a constituent of European barberry, has antiglycemic potential. Monitor blood glucose levels closely.

Likelihood Possible Evidence B

Antihypertensive Drugs

Theoretically, taking European barberry with antihypertensive drugs might increase the risk of hypotension.
Animal and human research suggests that European barberry extracts can have hypotensive effects.

Likelihood Possible Evidence D

Cholinergic Drugs

Theoretically, taking European barberry with cholinergic drugs might decrease the effects of cholinergic drugs.
In vitro evidence suggests that European barberry might have anticholinergic properties.

Likelihood Possible Evidence D

Cns Depressants

Theoretically, concomitant use with drugs that have sedative properties may cause additive effects.
Animal research suggests that berberine, a constituent of European barberry, might have sedative effects. Theoretically, European barberry might have a similar effect.

Likelihood Possible Evidence D

Cyclosporine (Neoral, Sandimmune)

Theoretically, concomitant use with cyclosporine may cause additive effects.
Berberine, a constituent of European barberry, can reduce the metabolism and increase serum levels of cyclosporine. This effect is attributed to the ability of berberine to inhibit cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporine. Theoretically, European barberry might have a similar effect.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, European barberry might increase the levels and clinical effects of CYP3A4 substrates.
There is very preliminary evidence suggesting that berberine, a constituent of European barberry, might inhibit the CYP3A4 enzyme. Theoretically, European barberry might have a similar effect.

Likelihood Possible Evidence D

Monograph

European Barberry: Uses, Safety & Side Effects

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

The bottom line

European barberry is a shrub whose root, bark, and berries contain berberine, a bitter plant alkaloid that has been studied mostly in isolated form. Some early research on berberine is promising for blood sugar and cholesterol, but high-quality evidence for the whole barberry herb is limited. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Scientific name: Berberis vulgaris
Family: Berberidaceae
Part used: Root, root bark, stem bark, leaf, and fruit (berries)
Common forms: Capsules, tablets, dried herb, tea, tincture/liquid extract, topical preparations

People commonly use it for

Digestive upset
Antimicrobial support
Blood sugar support
Cholesterol and metabolic support
Skin conditions

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

Safety at a glance

OverallUse caution

May be fine short-term for some people, but quality evidence on safe long-term use is 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

BreastfeedingLikely Unsafe

When used orally. Berberine and other harmful constituents can be transferred to the infant through breast milk.

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

European barberry (Berberis vulgaris) is a thorny shrub that produces small, tart red berries. It grows in parts of Asia, Europe, and North America. People have used different parts of the plant — the root, bark, leaf, and fruit — in traditional medicine for a long time.

The most studied compound in barberry is berberine, a yellow, bitter alkaloid. The bright red berries are also a source of vitamin C and have been used in cooking and to make jams in some regions.

Today, barberry and berberine are sold as dietary supplements in capsules, teas, tinctures, and topical products. Many of the popular health claims you may read about come from studies on purified berberine rather than the whole barberry plant.

How it works

Barberry contains several plant alkaloids, with berberine being the best known. In laboratory and animal studies, berberine appears to affect a cell energy sensor called AMPK, which may influence how the body handles sugar and fats. This is one proposed reason berberine has been studied for blood sugar and cholesterol.

Berberine has also shown antimicrobial activity against some bacteria, fungi, and parasites in lab tests, which may explain its traditional use for infections and digestive upset. It is also bitter, and bitter herbs have long been used to stimulate digestion.

Keep in mind that much of this research is from test tubes and animals. Effects seen in a lab do not always carry over to real benefits in people.

Effectiveness

Does European Barberry work?

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

Evidence overview · 10 uses evaluated

10 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.

For European Barberry, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 10 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Acne