Drug & supplement interaction

Gamma-linolenic Acid (gla) + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

Moderate Interaction
Medically reviewed by · Updated October 2026
The bottom line Moderate

Gamma-linolenic Acid (gla) has a moderate interaction with Warfarin Sodium. Theoretically, GLA might increase the risk of bleeding when taken with anticoagulant or antiplatelet rugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Gamma-linolenic Acid (gla) and Warfarin Sodium

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Warfarin Sodium

Warfarin Sodium falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Gamma-linolenic Acid (gla) interacts with.

Theoretically, GLA might increase the risk of bleeding when taken with anticoagulant or antiplatelet rugs.
Animal and human research suggests that GLA reduces platelet aggregation.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with warfarin and GLA (the omega-6 fatty acid in evening primrose and borage oils). GLA doesn't really change how your body breaks warfarin down. Instead, GLA may make your platelets a little less sticky on its own. Stack that on top of warfarin, which already lowers your blood's clotting ability, and the concern is simply additive: in theory you could bleed a bit more easily.

I'll be honest, this is a theoretical caution based on how GLA behaves, not strong human proof. Still, warfarin is a narrow-margin drug, so I take any bleeding signal seriously. Watch for easy bruising, nosebleeds, bleeding gums, or blood in urine or stool. Don't start or stop anything on your own. Loop in your pharmacist or the clinic that checks your INR first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Guivernau M, Meza N, Barja P, Roman O. Clinical and experimental study on the long-term effect of dietary gamma-linolenic acid on plasma lipids, platelet aggregation, thromboxane formation, and prostacyclin production. Prostaglandins Leukot Essent Fatty A PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Gamma-linolenic Acid (gla) Also Interacts With Other Medications

Gamma-linolenic Acid (gla) has 121 moderate known drug interactions in our database — the Warfarin Sodium one above is one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Gamma-linolenic Acid (gla)

Covers the 2,830 medications we’ve checked against Gamma-linolenic Acid (gla). Pick one to open its full report.

From our Q&A

Questions About Gamma-linolenic Acid (gla) or Warfarin Sodium

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Gamma-linolenic Acid (gla) or Warfarin Sodium, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Warfarin Sodium

This page covers Gamma-linolenic Acid (gla) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin Sodium page lists 361 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alfalfa (major), American Ginseng (major), Beer (major) and Cannabis (major).

Open the Warfarin Sodium interaction page

How much people look this up

Where Gamma-linolenic Acid (gla) and Warfarin Sodium Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Gamma-linolenic Acid (gla)
Top half

#490 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Warfarin Sodium
Top 1%

#22 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Gamma-linolenic Acid (gla)

What is Gamma-linolenic Acid (gla)?

  • Eczema and dry skin
  • Rheumatoid arthritis
  • Diabetic nerve pain
  • PMS and breast pain
  • Menopausal symptoms

Gamma-linolenic acid (GLA) is an omega-6 fatty acid found in oils like evening primrose and borage. It is most studied for skin conditions, joint pain, and nerve pain, but the evidence is mixed and far from conclusive. It is generally well tolerated, but talk with your pharmacist or doctor before starting, especially if you are pregnant, breastfeeding, or take other medicines.

Read the full Gamma-linolenic Acid (gla) monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand names: Coumadin, Panwarfin, Sofarin

Warfarin helps prevent and treat harmful blood clots. The label lists these uses for both Warfarin Sodium tablets and Jantoven tablets:

  • Preventing and treating venous thrombosis (clots in the veins) and pulmonary embolism (clots in the lungs).
  • Preventing and treating clot-related complications of atrial fibrillation and/or heart valve replacement.
  • Lowering the risk of death, another heart attack, and clot-related events such as stroke after a heart attack.

Warfarin does not dissolve a clot that has already formed. It helps stop the clot from growing and prevents further clot-related complications.

See full Warfarin drug information
Keep checking

Other Drugs & Gamma-linolenic Acid (gla)

Browse every other medication we’ve checked against Gamma-linolenic Acid (gla) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Gamma-linolenic Acid (gla) page.

No interaction 2,708 drugs checked — show the list

We also checked Gamma-linolenic Acid (gla) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Gamma-linolenic Acid (gla) list.

See the full Gamma-linolenic Acid (gla) interactions page
See every supplement checked against Warfarin Sodium, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Gamma-linolenic Acid (gla) monograph › Uses, safety, and every drug interaction in one place Warfarin Sodium supplement interactions › Every supplement checked against Warfarin Sodium, ranked by severity Warfarin drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Gamma-linolenic Acid (gla) and Warfarin Sodium Together: Common Questions

Can you take Gamma-linolenic Acid (gla) with Warfarin Sodium?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Gamma-linolenic Acid (gla) and Warfarin Sodium interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Warfarin Sodium and Gamma-linolenic Acid (gla)?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.