Drug & supplement interaction

Fish Oil + Selexipag

Selexipag brand name: Uptravi.

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

Selexipag falls into 2 drug categories that Fish Oil can interact with; the most serious is rated moderate. Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Fish Oil and Selexipag

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Fish Oil interacts with whole categories of medication. Selexipag falls into 2 of those categories, so it can interact with Fish Oil in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Selexipag

Selexipag falls under ANTIHYPERTENSIVE DRUGS — the group Fish Oil interacts with.

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.
Clinical evidence indicates that fish oils can modestly lower blood pressure and might have additive effects in patients treated with antihypertensives.
Severity Moderate Likelihood Probable Evidence B

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..

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

Here's the simple version: fish oil can gently nudge your blood pressure down on its own. Since selexipag (Uptravi) works by relaxing the blood vessels in your lungs, the two together could add up and lower your blood pressure a bit more than expected. This isn't about fish oil changing how your body breaks selexipag down, it's just two things pulling in the same direction.

What that might feel like is more lightheadedness, dizziness when you stand up, headache, or flushing. The effect is usually mild, and the evidence here is fairly modest. You don't need to panic, but please don't start or stop either one on your own. Check with your pharmacist or doctor first, especially if you already feel dizzy.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Prisco D, Paniccia R, Bandinelli B, et al. Effect of medium-term supplementation with a moderate dose of n-3 polyunsaturated fatty acids on blood pressure in mild hypertensive patients. Thromb Res 1998;1:105-12.
  2. Toft I, Bonaa KH, Ingebretsen OC, et al. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. A randomized, controlled trial. Ann Intern Med 1995;123:911-8.
  3. Sacks FM, Hebert P, Appel LJ, et al. Short report: the effect of fish oil on blood pressure and high-density lipoprotein-cholesterol levels in phase I of the trials of hypertension prevention. J Hypertens 1994;12:209-13.
  4. Vandongen R, Mori TA, Burke V, et al. Effects on blood pressure of omega 3 fats in subjects at increased risk of cardiovascular disease. Hypertension 1993;22:371-9. PubMed
  5. Bonaa, K. H., Bjerve, K. S., Straume, B., Gram, I. T., and Thelle, D. Effect of eicosapentaenoic and docosahexaenoic acids on blood pressure in hypertension. A population-based intervention trial from the Tromso study. N Engl J Med 3-22-1990;322(12):795- DOI
  6. Singer, P., Melzer, S., Goschel, M., and Augustin, S. Fish oil amplifies the effect of propranolol in mild essential hypertension. Hypertension 1990;16(6):682-691. PubMed
  7. Knapp, H. R. and FitzGerald, G. A. The antihypertensive effects of fish oil. A controlled study of polyunsaturated fatty acid supplements in essential hypertension. N Engl J Med 4-20-1989;320(16):1037-1043. PubMed
  8. Lungershausen, Y. K., Abbey, M., Nestel, P. J., and Howe, P. R. Reduction of blood pressure and plasma triglycerides by omega-3 fatty acids in treated hypertensives. J Hypertens. 1994;12(9):1041-1045. DOI
  9. Appel, L. J., Miller, E. R., III, Seidler, A. J., and Whelton, P. K. Does supplementation of diet with 'fish oil' reduce blood pressure? A meta-analysis of controlled clinical trials. Arch Intern Med 6-28-1993;153(12):1429-1438. DOI
  10. Morris, M. C., Sacks, F., and Rosner, B. Does fish oil lower blood pressure? A meta-analysis of controlled trials. Circulation 1993;88(2):523-533. PubMed
  11. Morris, M. C., Taylor, J. O., Stampfer, M. J., Rosner, B., and Sacks, F. M. The effect of fish oil on blood pressure in mild hypertensive subjects: a randomized crossover trial. Am J Clin Nutr 1993;57(1):59-64. PubMed
Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 2

Selexipag also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Fish oil may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs. However, evidence is conflicting.
While fish oil may not be a potent inhibitor of platelet function, high doses of fish oil might have antiplatelet effects. Theoretically, concomitant use of fish oil with anticoagulant or antiplatelet drugs may increase the risk of bleeding. However, the most rigorous research shows that short-term doses of fish oil 10 grams daily or long-term doses of 1.5 grams daily for up to 52 weeks does not increase the risk of bleeding or affect coagulation parameters in chronically ill and vulnerable patients. Other controlled research shows that fish oil does not affect platelet function or increase the risk of bleeding. Some research even suggests that perioperative fish oil use decreases bleeding risk. Some research suggests fish oil does not have additive antiplatelet effects when combined with aspirin, but other clinical evidence suggests that adding fish oil to low-dose aspirin treatment increases antiplatelet effects in patients who are aspirin-resistant. Also, some clinical research seems to show that fish oil has additive antiplatelet effects when used with aspirin and clopidogrel compared to aspirin and clopidogrel alone.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the thing to know about this pairing: the bleeding concern on file is really about fish oil's mild blood-thinning tendency at higher doses, and it's grouped with antiplatelet medicines. Selexipag (Uptravi) itself is not a true blood thinner, so the two don't add up the way fish oil plus aspirin or warfarin might. The evidence here is also weak and conflicting, and most solid research shows fish oil doesn't meaningfully raise bleeding risk on its own.

What I'd actually watch for with selexipag are its own common effects, like headache, flushing, jaw pain, nausea, or diarrhea, since fish oil won't change those. Everyday food amounts of fish are no worry at all. Still, before adding a concentrated fish oil supplement, it's worth a quick chat with your pharmacist or doctor so they can look at your full medication list.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Leaf A. On the reanalysis of the GISSI-Prevenzione. Circulation 2002;105:1874-5. PubMed
  2. Connor WE. n-3 Fatty acids from fish and fish oil: panacea or nostrum? Am J Clin Nutr 2001;74;415-6. PubMed
  3. Calder PC. N-3 polyunsaturated fatty acids, inflammation and immunity: pouring oil on troubled waters or another fishy tale? Nutr Res 2001;21:309-41. DOI
  4. Svaneborg N, Kristensen SD, Hansen LM, et al. The acute and short-time effect of supplementation with the combination of n-3 fatty acids and acetylsalicylic acid on platelet function and plasma lipids. Thromb Res 2002;105:311-6. PubMed
  5. Kwak SM, Myung SK, Lee YJ, Seo HG. Efficacy of omega-3 fatty acid supplements (eicosapentaenoic acid and docosahexaenoic acid) in the secondary prevention of cardiovascular disease: a meta-analysis of randomized, double-blind, placebo-controlled trials. A PubMed
  6. Armaganijan L, Lopes RD, Healey JS, et al. Do omega-3 fatty acids prevent atrial fibrillation after open heart surgery? A meta-analysis of randomized controlled trials. Clinics (Sao Paulo) 2011;66:1923-8.
  7. von Houwelingen R, Nordøy A, van der Beek E, et al. Effect of a moderate fish intake on blood pressure, bleeding time, hematology, and clinical chemistry in healthy males. Am J Clin Nutr. 1987 Sep;46(3):424-36. PubMed
  8. Goodnight SH Jr, Harris WS, Connor WE. The effects of dietary omega 3 fatty acids on platelet composition and function in man: a prospective, controlled study. Blood. 1981 Nov;58(5):880-5. DOI
  9. Gajos G1, Rostoff P, Undas A, et al. Effects of polyunsaturated omega-3 fatty acids on responsiveness to dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: the OMEGA-PCI (OMEGA-3 fatty acids after pci to modify responsive
  10. Lev EI, Solodky A, Harel N, et al. Treatment of aspirin-resistant patients with omega-3 fatty acids versus aspirin dose escalation. J Am Coll Cardiol. 2010 Jan 12;55(2):114-21. DOI
  11. Salvig, J. D. and Lamont, R. F. Evidence regarding an effect of marine n-3 fatty acids on preterm birth: a systematic review and meta-analysis. Acta Obstet.Gynecol.Scand. 2011;90(8):825-838. PubMed
  12. Zucker, M. L., Bilyeu, D. S., Helmkamp, G. M., Harris, W. S., and Dujovne, C. A. Effects of dietary fish oil on platelet function and plasma lipids in hyperlipoproteinemic and normal subjects. Atherosclerosis 1988;73(1):13-22. PubMed
  13. Demke, D. M., Peters, G. R., Linet, O. I., Metzler, C. M., and Klott, K. A. Effects of a fish oil concentrate in patients with hypercholesterolemia. Atherosclerosis 1988;70(1-2):73-80. PubMed
  14. Mozaffarian D, Wu JH, de Oliveira Otto MC, Sandesara CM, Metcalf RG, Latini R, Libby P, Lombardi F, O'Gara PT, Page RL, Silletta MG, Tavazzi L, Marchioli R. Fish oil and post-operative atrial fibrillation: a meta-analysis of randomized controlled trials. PubMed
  15. Xin W, Wei W, Lin Z, Zhang X, Yang H, Zhang T, Li B, Mi S. Fish oil and atrial fibrillation after cardiac surgery: a meta-analysis of randomized controlled trials. PLoS One 2013;8(9):e72913. PubMed
  16. Jeansen S, Witkamp RF, Garthoff JA, van Helvoort A, Calder PC. Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: Analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition. Cli PubMed
  17. Fradet S, Pelletier JF, Singbo N, et al. Effects of omega-3 fatty acids supplementation on perioperative blood loss and complications after radical prostatectomy. Clin Nutr ESPEN 2022;47:221-226. 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

Fish Oil Also Interacts With Other Medications

Fish Oil has 206 moderate, 120 minor known drug interactions in our database — the Selexipag one above is among them. If you take anything else, check it against the full list below.

Moderate 206 Minor 120 No known interaction 2,504 (incl. Selexipag)
Taking anything else?

Check Another of Your Medications Against Fish Oil

Covers the 2,830 medications we’ve checked against Fish Oil. Pick one to open its full report.

From our Q&A

Questions About Fish Oil or Selexipag

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Fish Oil or Selexipag, 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 Selexipag

This page covers Fish Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selexipag page lists 291 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Danshen (major) and Piracetam (major).

By severity: 6 major · 258 moderate · 27 minor.

From our pharmacist’s overview on the Selexipag page

“People take selexipag (Uptravi) for pulmonary arterial hypertension, dangerously high pressure in the arteries of the lungs, and that diagnosis raises the stakes on this list of 291 interacting supplements. I would treat it with real vigilance.”

Reviewed by 2 · Jul 18, 2026

Open the Selexipag interaction page

One more smart check

Taking Fish Oil as Part of a Dietary Supplement Product? Check It for Interactions

We hold 4,777 real supplement products containing Fish Oil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fish Oil. Your product may carry other ingredients that interact with Selexipag too, on top of Fish Oil — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Fish Oil and Selexipag 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 Fish Oil
Top 5%

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

29 days ago today
Medication Selexipag
Top 25%

#353 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 Fish Oil

What is Fish Oil?

Fish Oil
  • High triglycerides
  • Heart health
  • Joint pain and inflammation
  • Brain and eye health
  • Dry eyes

Fish oil provides omega-3 fatty acids (EPA and DHA) that are best known for lowering high triglyceride levels. The evidence for other heart and health benefits is mixed, and it is generally well tolerated. Talk with your pharmacist or doctor before starting it, especially if you take blood thinners or have a fish allergy.

Read the full Fish Oil monograph & all interactions
Medication

About Selexipag

What Is Selexipag Used For?

Brand name: Uptravi

Selexipag tablets are used to treat pulmonary arterial hypertension (PAH, WHO Group I) — a type of high blood pressure in the arteries of the lungs. The goal is to slow the disease from getting worse and to reduce the chances of being hospitalized because of PAH.

Uptravi (selexipag) tablets are approved for both adults and children aged 2 years and older. Uptravi for injection (intravenous) is also available for adult patients who are already on Uptravi tablets but temporarily cannot take medicine by mouth.

See full Selexipag drug information
Keep checking

Other Drugs & Fish Oil

Browse every other medication we’ve checked against Fish Oil — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
206Moderate
120Minor
2,503No known interaction
206 Moderate 120 Minor 2,503 No interaction
Moderate

206 interactions

Showing 60 of 206 moderate interactions — see all 206 on the Fish Oil page.

Minor

120 interactions

Showing 60 of 120 minor interactions — see all 120 on the Fish Oil page.

No interaction 2,503 drugs checked — show the list

We also checked Fish Oil against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,503 medications checked with no known interaction — see the full Fish Oil list.

See the full Fish Oil interactions page
See every supplement checked against Selexipag, 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
Fish Oil monograph › Uses, safety, and every drug interaction in one place Selexipag supplement interactions › Every supplement checked against Selexipag, ranked by severity Selexipag 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 Fish Oil and Selexipag Together: Common Questions

Can you take Fish Oil with Selexipag?
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.
Why are there 2 interactions listed for Fish Oil and Selexipag?
Selexipag belongs to more than one drug category, and Fish Oil interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Fish Oil and Selexipag 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 Selexipag and Fish Oil?

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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.