Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Black Currant 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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Black Currant 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 Black Currant drug interaction appears low for most people. None of the listed interactions are rated major, and all of them rest on theoretical concerns rather than documented problems in people.

Interactions deserving the most attention

The combinations most worth attention involve anticoagulant or antiplatelet drugs, because a fatty acid in black currant seed oil may have mild blood-thinning effects that could add to medications affecting bleeding. There is also a theoretical concern with phenothiazines, a group of antipsychotic medicines, since that same fatty acid has been linked to a possible lowering of the seizure threshold, though black currant seed oil itself has not been shown to cause seizures. Neither concern is backed by strong human evidence.

What the rest of the list means

Although the list of interacting medications is long, that does not mean each combination is harmful. Nearly all of these entries trace back to the same theoretical concerns about one component of black currant seed oil, based mostly on lab research. So far, these predicted effects have not been confirmed as meaningful problems in people.

Check your medications against Black Currant

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

Interaction report

Drugs that interact with Black Currant

140 medications have a known interaction with Black Currant, 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 Black Currant using our pharmacist-reviewed interaction data.

AI summaries are generated from our Black Currant 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 Black Currant 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 Black Currant affects

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

All 2 drug categories Black Currant interacts with

Anticoagulant/antiplatelet DrugsPhenothiazines

Anticoagulant/Antiplatelet Drugs

Theoretically, black currant seed oil might increase the risk of bleeding if used in combination with anticoagulant or antiplatelet drugs.
Gamma-linolenic acid (GLA), a constituent of black currant seed oil, appears to have antiplatelet effects.

Likelihood Possible Evidence D

Phenothiazines

Theoretically, black currant seed oil might increase the risk of seizure in patients receiving phenothiazines.
Black currant seed oil contains gamma-linolenic acid (GLA). There is some concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines, although there is no evidence that black currant seed oil causes seizures. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with GLA, although none experienced an actual seizure. In another report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose 4 grams daily, which contains GLA, was added. One of these patients had a prior history of seizures.

Likelihood Possible Evidence D

Monograph

Black Currant: Uses, Safety & Side Effects

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

The bottom line

Black currant is a nutritious berry that is rich in vitamin C and antioxidants, and its seed oil contains the omega-6 fatty acid GLA. While it is enjoyed safely as a food and is popular as a supplement, solid human evidence for most health claims is still limited. Talk with your pharmacist or doctor before using concentrated supplements, especially if you are pregnant, nursing, or have a medical condition.

Scientific name: Ribes nigrum
Family: Grossulariaceae
Part used: Berries (fruit), seeds (seed oil), and leaves
Common forms: Whole berries, juice, capsules, seed oil softgels, dried leaf for tea, extracts

People commonly use it for

Dry eyes and eye strain
Joint pain and inflammation
Immune and general wellness support
Cardiovascular health
Skin conditions (such as dry skin or eczema)

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

Safety at a glance

OverallUse caution

The berry is safe as a food, but concentrated supplements are less studied and should be used carefully.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

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.

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Overview

Black currant (Ribes nigrum) is a small shrub native to Europe and parts of northern Asia. It produces dark purple, sweet-tart berries that are popular in jams, juices, syrups, and as a flavoring agent (often called "cassis").

The berries are a good source of vitamin C, fiber, and colorful plant pigments called anthocyanins. Besides the fruit, the seeds are pressed into an oil that is rich in gamma-linolenic acid (GLA), an omega-6 fatty acid. The leaves are also used traditionally to make teas and extracts.

People take black currant in many forms, including fresh or dried berries, juice, capsules, leaf tea, and seed oil softgels.

How it works

Black currant contains several compounds that may explain its proposed effects. These mechanisms are mostly based on laboratory and animal research, and they do not always translate into real benefits in people.

The main active compounds include:

Anthocyanins: The dark purple pigments that act as antioxidants and may help protect cells and support blood vessels.
Vitamin C: An antioxidant that supports normal immune function and skin health.
Gamma-linolenic acid (GLA): An omega-6 fatty acid found in the seed oil that the body can convert into substances involved in controlling inflammation.

Researchers believe these compounds may reduce oxidative stress and influence inflammation, but more human studies are needed to confirm how meaningful these effects are.

Effectiveness

Does Black Currant work?

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

Evidence overview · 27 uses evaluated

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

Also studied for 27 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Alzheimer disease