Drug & supplement interaction

Algal Oil + Amiloride, Hydrochlorothiazide

Amiloride, Hydrochlorothiazide brand names: Moduretic, Amilzide, Moduret 25, Amil-Co.

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

Algal Oil has a moderate interaction with Amiloride, Hydrochlorothiazide. Theoretically, taking algal oil with antihypertensive drugs might increase the risk of hypotension.

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

Algal Oil and Amiloride, Hydrochlorothiazide

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Amiloride, Hydrochlorothiazide

Amiloride, Hydrochlorothiazide 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 gist: your amiloride and hydrochlorothiazide combo (Moduretic) lowers your blood pressure by helping your kidneys flush out extra salt and water. The omega-3 fats in algal oil (DHA and EPA) may nudge blood pressure down a little on their own. Put them together and, in theory, the two could add up and drop your numbers a bit more than expected.

I'll be straight with you, this is a theoretical concern based on how these work, not something proven to cause big problems. Still, watch for signs your pressure dipped too low, like feeling dizzy, lightheaded, or faint when you stand up. If that happens, give your pharmacist or doctor a call before changing anything.

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.

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 Amiloride, Hydrochlorothiazide one above is one of them. If you take anything else, check it against the full list below.

Moderate 257 Minor 117 No known interaction 2,456 (incl. Amiloride, Hydrochlorothiazide)
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 Amiloride, Hydrochlorothiazide

This page covers Algal Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Amiloride, Hydrochlorothiazide page lists 236 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), Asarabacca (major) and Dolomite (major).

By severity: 10 major · 199 moderate · 27 minor.

From our pharmacist’s overview on the Amiloride, Hydrochlorothiazide page

“The typical Moduretic (amiloride with hydrochlorothiazide) patient is managing blood pressure long term, and the supplements that crowd reaches for (herbal blood pressure aids, potassium, calcium) are exactly what fills this list. It deserves a careful read, not a skim.”

Reviewed by 2 · Jul 18, 2026

Open the Amiloride, Hydrochlorothiazide 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 Amiloride, Hydrochlorothiazide 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 Amiloride, Hydrochlorothiazide 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 25%

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

29 days ago today
Medication Amiloride, Hydrochlorothiazide
Top 10%

#200 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 Amiloride and Hydrochlorothiazide

What Is Amiloride and Hydrochlorothiazide Used For?

Brand names: Moduretic, Amilzide, Moduret 25, Amil-Co

Amiloride hydrochloride and hydrochlorothiazide tablets are used for patients with high blood pressure (hypertension) or congestive heart failure who tend to develop low potassium (hypokalemia) when taking a thiazide or other diuretic alone — or for whom keeping potassium levels in a normal range is especially important, such as people taking digoxin or those with significant heart rhythm problems.

The tablets may be used on their own or alongside other blood pressure medicines, such as methyldopa or beta blockers. This combination product is not intended as the first-choice treatment for swelling (edema) or high blood pressure unless low potassium is a specific concern.

See full Amiloride and Hydrochlorothiazide 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 Amiloride, Hydrochlorothiazide, 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 Amiloride, Hydrochlorothiazide supplement interactions › Every supplement checked against Amiloride, Hydrochlorothiazide, ranked by severity Amiloride and Hydrochlorothiazide 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 Amiloride, Hydrochlorothiazide Together: Common Questions

Can you take Algal Oil with Amiloride, Hydrochlorothiazide?
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 Algal Oil and Amiloride, Hydrochlorothiazide 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 Amiloride, Hydrochlorothiazide 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.