Drug & supplement interaction

Algal 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 Algal Oil can interact with; the most serious is rated moderate. Theoretically, taking algal oil with antihypertensive drugs might increase the risk of hypotension.

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

Algal Oil and Selexipag

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

Why Are There 2 Interactions?

Algal Oil interacts with whole categories of medication. Selexipag falls into 2 of those categories, so it can interact with Algal 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 Algal Oil interacts with.

Theoretically, taking algal oil with antihypertensive drugs might increase the risk of hypotension.
Algal oil usually contains docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA). There is evidence that fish oil, which also contains DHA and EPA, can modestly lower blood pressure and might have additive effects in patients treated with antihypertensive drugs.
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 simple version: omega-3 fats like the DHA and EPA in algal oil can nudge blood pressure down a little on their own. Since selexipag (Uptravi) works by relaxing the blood vessels in your lungs, the worry is that the two together might lower your blood pressure a bit more than expected. If that happened, you could feel things like dizziness, lightheadedness, a flushed feeling, or a headache, especially when you stand up quickly.

I want to be honest about how solid this is: it's a theoretical concern based on how these work, not something seen often in real patients, and culinary amounts matter far less than concentrated supplement doses. Still, since PAH is serious, please run algal oil by your pharmacist or doctor before adding it so they can keep an eye on your symptoms.

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. Mori, T. A., Bao, D. Q., Burke, V., Puddey, I. B., and Beilin, L. J. Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans. Hypertension 1999;34(2):253-260. PubMed
  6. Nestel, P., Shige, H., Pomeroy, S., Cehun, M., Abbey, M., and Raederstorff, D. The n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid increase systemic arterial compliance in humans. Am.J.Clin.Nutr. 2002;76(2):326-330. PubMed
  7. Woodman, R. J., Mori, T. A., Burke, V., Puddey, I. B., Barden, A., Watts, G. F., and Beilin, L. J. Effects of purified eicosapentaenoic acid and docosahexaenoic acid on platelet, fibrinolytic and vascular function in hypertensive type 2 diabetic patients PubMed
  8. Theobald, H. E., Goodall, A. H., Sattar, N., Talbot, D. C., Chowienczyk, P. J., and Sanders, T. A. Low-dose docosahexaenoic acid lowers diastolic blood pressure in middle-aged men and women. J Nutr 2007;137(4):973-978.
Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 2

Selexipag also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Theoretically, algal oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
The risk of interaction is highest for algal oil containing high amounts (> 2 grams daily) of eicosapentaenoic acid (EPA), or EPA and docosahexaenoic acid (DHA). High doses of EPA or oils containing EPA and DHA can reduce platelet aggregation in humans. However, most algal oil contains very little EPA and larger amounts of DHA. While some conflicting evidence exist, most research shows that DHA alone does not affect blood clotting.
Severity Minor Likelihood Unlikely Evidence D

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 honest picture: this flag comes from grouping selexipag (Uptravi) with blood thinners, since omega-3 fats can make platelets a little less sticky at high doses. But the science behind it is theoretical, and the bleeding risk is rated minor and unlikely. The bigger point is that high-dose EPA is what may nudge clotting, and most algal oil is mostly DHA, which by itself usually doesn't affect bleeding.

Selexipag isn't a typical anticoagulant, but as a prostacyclin pathway drug it can already cause some bruising and bleeding tendency. So if you take a concentrated algal oil and notice easy bruising, nosebleeds, or bleeding gums, mention it. Always check with your pharmacist or doctor before starting it.

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. Terano T, Hirai A, Hamazaki T, et al. Effect of oral administration of highly purified eicosapentaenoic acid on platelet function, blood viscosity and red cell deformability in healthy human subjects. Atherosclerosis 1983;46:321-31.. PubMed
  5. Leng GC, Smith FB, Fowkes FG, et al. Relationship between plasma essential fatty acids and smoking, serum lipids, blood pressure and haemostatic and rheological factors. Prostaglandins Leukot Essent Fatty Acids 1994;51:101-8. PubMed
  6. Nelson GJ, Schmidt PS, Bartolini GL, et al. The effect of dietary docosahexaenoic acid on platelet function, platelet fatty acid composition, and blood coagulation in humans. Lipids 1997;32:1129-36. PubMed
  7. 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
  8. 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
  9. 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
  10. Woodman, R. J., Mori, T. A., Burke, V., Puddey, I. B., Barden, A., Watts, G. F., and Beilin, L. J. Effects of purified eicosapentaenoic acid and docosahexaenoic acid on platelet, fibrinolytic and vascular function in hypertensive type 2 diabetic patients PubMed
  11. 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

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

Algal Oil Also Interacts With Other Medications

Algal Oil has 257 moderate, 117 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 257 Minor 117 No known interaction 2,456 (incl. Selexipag)
Taking anything else?

Check Another of Your Medications Against Algal Oil

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

Everything else you take

See Every Supplement That Interacts With Selexipag

This page covers Algal 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 Algal Oil as Part of a Dietary Supplement Product? Check It for Interactions

We hold 188 real supplement products containing Algal Oil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Algal Oil. Your product may carry other ingredients that interact with Selexipag too, on top of Algal 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 Algal 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 Algal Oil
Top half

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

29 days ago today
Medication Selexipag
Top half

#1,226 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 Algal Oil

What is Algal Oil?

Algal Oil
  • Vegan/vegetarian source of omega-3s (DHA and EPA)
  • Heart and triglyceride health
  • Brain and eye support
  • Pregnancy and infant nutrition
  • General anti-inflammatory support

Algal oil is a plant-based source of the omega-3 fats DHA and (in some products) EPA, making it a popular alternative to fish oil for vegetarians, vegans, and people who dislike fish. There is reasonable evidence that omega-3s can lower triglycerides and support heart and brain health, though more research is needed for many specific uses. It is generally well tolerated, but check with your pharmacist or doctor before starting, especially if you take blood thinners or are pregnant.

Read the full Algal 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 & Algal Oil

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

0Major
257Moderate
117Minor
2,455No known interaction
257 Moderate 117 Minor 2,455 No interaction
Moderate

257 interactions

Showing 60 of 257 moderate interactions — see all 257 on the Algal Oil page.

Minor

117 interactions

Showing 60 of 117 minor interactions — see all 117 on the Algal Oil page.

No interaction 2,455 drugs checked — show the list

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

Showing the 60 most looked-up of 2,455 medications checked with no known interaction — see the full Algal Oil list.

See the full Algal 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
Algal 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 Algal Oil and Selexipag Together: Common Questions

Can you take Algal 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 Algal Oil and Selexipag?
Selexipag belongs to more than one drug category, and Algal 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 Algal 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 Algal 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.