Drug & supplement interaction

Eicosapentaenoic Acid (epa) + Hydralazine

Hydralazine brand names: Apresoline, Hylazin, Hydralazine, Dralzine, Apresoline Injection.

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

Eicosapentaenoic Acid (epa) has a moderate interaction with Hydralazine. Theoretically, taking EPA with antihypertensive drugs might increase the risk of hypotension.

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

Eicosapentaenoic Acid (epa) and Hydralazine

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Hydralazine

Hydralazine falls under ANTIHYPERTENSIVE DRUGS — the group Eicosapentaenoic Acid (epa) interacts with.

Theoretically, taking EPA with antihypertensive drugs might increase the risk of hypotension.
Fish oils containing EPA can lower blood pressure and might have additive effects in patients treated with antihypertensives; use with caution.
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: EPA from fish oil can gently lower blood pressure on its own. Since hydralazine already relaxes your blood vessels to bring your numbers down, stacking the two could push your pressure a little lower than expected. That's the concern here, an additive effect, not the supplement changing how your body processes the drug.

If your blood pressure drops too far, you might feel dizzy or lightheaded (especially when standing up fast), tired, or get a faster heartbeat, which can happen with hydralazine anyway. For most people this is mild, and the evidence behind it is fairly modest. Food amounts of fatty fish are unlikely to matter much, but concentrated fish oil capsules are more likely to add up. Don't stop or change anything on your own, just check in with your pharmacist or doctor first.

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

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

Eicosapentaenoic Acid (epa) Also Interacts With Other Medications

Eicosapentaenoic Acid (epa) has 288 moderate known drug interactions in our database — the Hydralazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 288 No known interaction 2,542 (incl. Hydralazine)
Taking anything else?

Check Another of Your Medications Against Eicosapentaenoic Acid (epa)

Covers the 2,830 medications we’ve checked against Eicosapentaenoic Acid (epa). Pick one to open its full report.

From our Q&A

Questions About Eicosapentaenoic Acid (epa) or Hydralazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Eicosapentaenoic Acid (epa) or Hydralazine, 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 Hydralazine

This page covers Eicosapentaenoic Acid (epa) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydralazine page lists 136 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), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 111 moderate · 21 minor.

From our pharmacist’s overview on the Hydralazine page

“Hydralazine is the drug doctors reach for when blood pressure needs forcing down, so I read this list of 136 supplement interactions with genuine concern rather than routine caution. Start with the four rated major: two are toxic plants with direct effects on the heart and blood vessels, tyramine can push pressure back up and undo the…”

Reviewed by 2 · Jul 18, 2026

Open the Hydralazine interaction page

How much people look this up

Where Eicosapentaenoic Acid (epa) and Hydralazine 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 Eicosapentaenoic Acid (epa)
Steady interest

#1,320 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Hydralazine
Steady interest

#1,545 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 Eicosapentaenoic Acid (epa)

What is Eicosapentaenoic Acid (epa)?

  • Heart and triglyceride health
  • Inflammation
  • Mood and depression support
  • Joint comfort
  • General omega-3 supplementation

EPA is an omega-3 fatty acid found mostly in fatty fish and fish oil, and it is best known for lowering high triglycerides. It may also help with inflammation and mood in some people, but evidence varies by condition. Talk with your pharmacist or doctor before starting, especially if you take blood thinners or have a fish allergy.

Read the full Eicosapentaenoic Acid (epa) monograph & all interactions
Medication

About Hydralazine

What Is Hydralazine Used For?

Brand names: Apresoline, Hylazin, Hydralazine, Dralzine, Apresoline Injection

Hydralazine tablets are used to treat essential hypertension (high blood pressure), either alone or alongside other blood pressure medications.

The hydrALAZINE Hydrochloride injection form is used in hospital settings for severe essential hypertension when oral medication cannot be taken or when blood pressure needs to be lowered urgently.

See full Hydralazine drug information
Keep checking

Other Drugs & Eicosapentaenoic Acid (epa)

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

0Major
288Moderate
0Minor
2,541No known interaction
288 Moderate 2,541 No interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Eicosapentaenoic Acid (epa) page.

No interaction 2,541 drugs checked — show the list

We also checked Eicosapentaenoic Acid (epa) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,541 medications checked with no known interaction — see the full Eicosapentaenoic Acid (epa) list.

See the full Eicosapentaenoic Acid (epa) interactions page
See every supplement checked against Hydralazine, 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
Eicosapentaenoic Acid (epa) monograph › Uses, safety, and every drug interaction in one place Hydralazine supplement interactions › Every supplement checked against Hydralazine, ranked by severity Hydralazine 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 Eicosapentaenoic Acid (epa) and Hydralazine Together: Common Questions

Can you take Eicosapentaenoic Acid (epa) with Hydralazine?
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 Eicosapentaenoic Acid (epa) and Hydralazine 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 Hydralazine and Eicosapentaenoic Acid (epa)?

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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.