Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Borage 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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Borage 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 Borage drug interaction appears low for most people. None of the listed interactions are rated major, and every one rests on theoretical or limited evidence rather than well-documented effects in people.

Interactions deserving the most attention

The combination that deserves the most care is borage with anticoagulant or antiplatelet drugs, since a fatty acid in borage seed oil reduced platelet clumping in some research, which could add to bleeding risk, even though studies in healthy people showed no effect. There is also an old, limited concern that borage seed oil could lower the seizure threshold when taken with phenothiazines. Finally, some borage plant parts (though not typically the seed oil) contain compounds that certain medications may convert into liver-toxic byproducts, so borage leaf or flower is best avoided with those drugs.

What the rest of the list means

Although borage is linked to a long list of medications, that number comes from a few broad drug categories, not hundreds of separate proven problems. Nearly all of these concerns are theoretical, based on what borage's components might do in the body, and some predicted effects, such as changes in platelet function, have not appeared in studies of healthy people.

Check your medications against Borage

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

Interaction report

Drugs that interact with Borage

226 medications have a known interaction with Borage, 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 Borage using our pharmacist-reviewed interaction data.

AI summaries are generated from our Borage 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 Borage 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 Borage affects

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

All 3 drug categories Borage interacts with

Anticoagulant/antiplatelet DrugsCytochrome P450 3a4 (cyp3a4) InducersPhenothiazines

Anticoagulant/Antiplatelet Drugs

Theoretically, borage seed oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In healthy individuals, borage seed oil supplementation does not seem to affect platelet aggregation. However, gamma-linolenic acid, a constituent of borage seed oil, seems to decrease platelet aggregation by 45% and increase the risk of bleeding by 40% in animal and clinical research.

Likelihood Possible Evidence B

Cytochrome P450 3A4 (Cyp3A4) Inducers

Theoretically, taking borage with drugs that induce CYP3A4 might increase levels of pyrrolizidine alkaloid (PA) toxic metabolites.
Although borage seed oil contains little to no PAs, some borage plant parts, such as the leaf, flower, and seed, can contain hepatotoxic PAs. Hepatotoxic PAs are substrates of CYP3A4, which converts these chemicals into toxic metabolites. Tell patients to avoid borage preparations that are not certified and labeled as hepatotoxic PA-free.

Likelihood Possible Evidence D

Phenothiazines

Theoretically, taking borage sed oil with phenothiazines might increase the risk of seizures.
Borage seed oil contains gamma-linolenic acid (GLA). There is concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines. This is based on limited data from two reports published in the 1980s. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with evening primrose, another source of GLA. However, none experienced an actual seizure. In the other report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose 4 grams daily was added. One of these patients had a prior history of seizures. It is unclear whether evening primrose had any additive epileptogenic effects with the phenothiazines, but there is no evidence that taking GLA-containing supplements alone can cause seizures.

Likelihood Possible Evidence D

Monograph

Borage: Uses, Safety & Side Effects

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

The bottom line

Borage is a Mediterranean herb whose seed oil is rich in gamma-linolenic acid (GLA), an omega-6 fatty acid studied mostly for skin conditions and arthritis with mixed results. The plant's leaves and flowers can contain liver-toxic pyrrolizidine alkaloids, so only use products clearly labeled 'PA-free' and talk to your pharmacist or doctor before taking it.

Scientific name: Borago officinalis
Family: Boraginaceae
Part used: Seeds (for oil), leaves, and flowers
Common forms: Borage seed oil capsules, topical oil, tea, dried leaf/flower

People commonly use it for

Eczema and dry skin
Rheumatoid arthritis
Inflammation
Respiratory complaints
Mood and stress

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

Safety at a glance

OverallUse caution

Seed oil that is certified pyrrolizidine alkaloid (PA)-free is generally better tolerated, but other parts may harm the liver.

PregnancyLikely Unsafe

When products containing hepatotoxic pyrrolizidine alkaloids (PA) are used orally. Borage plant parts, such as the leaf, flower, and seed, can contain...

Read the full pregnancy detail

BreastfeedingLikely Unsafe

When products containing hepatotoxic pyrrolizidine alkaloids (PA) are used orally. Borage plant parts, such as the leaf, flower, and seed, can contain...

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

Borage (Borago officinalis) is a flowering herb native to the Mediterranean region but now grown in many parts of the world. It is easy to recognize by its bright blue, star-shaped flowers and its rough, hairy leaves and stems.

The herb has a long history in traditional medicine, where the leaves and flowers were used for breathing problems, fever, mood, and other complaints. Today, the most common product is borage seed oil, which is pressed from the plant's seeds and is one of the richest plant sources of gamma-linolenic acid (GLA), an omega-6 fatty acid.

People take borage seed oil as a capsule or apply it to the skin. Dried leaves and flowers are sometimes used as a tea or in cooking, though this raises safety concerns discussed below.

How it works

The main active ingredient in borage seed oil is gamma-linolenic acid (GLA). The body converts GLA into substances that may help calm inflammation. This is the proposed reason it has been studied for inflammatory conditions like eczema and arthritis.

The leaves and flowers also contain mucilage (a gel-like substance) and other plant compounds that were traditionally thought to soothe tissues. Much of what we know about how borage's compounds act comes from laboratory and animal research, so the effects in people are not fully proven.

Effectiveness

Does Borage work?

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

Evidence overview · 19 uses evaluated

1 Leans ineffective 18 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 Atopic dermatitis (eczema)