Drug & supplement interaction

Dulse + Captopril, Hydrochlorothiazide

Captopril, Hydrochlorothiazide brand names: Capozide, Acezide.

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

Dulse has a minor interaction with Captopril, Hydrochlorothiazide. Theoretically, dulse might increase the risk of hyperkalemia when taken with ACEIs.

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

Dulse and Captopril, Hydrochlorothiazide

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

Minor

ACE INHIBITORS (ACEIs)

Why this applies to Captopril, Hydrochlorothiazide

Captopril, Hydrochlorothiazide falls under ACE INHIBITORS (ACEIs) — the group Dulse interacts with.

Theoretically, dulse might increase the risk of hyperkalemia when taken with ACEIs.
Dulse is rich in potassium. ACEIs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion. Concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels. However, using these drugs while consuming dulse in quantities that provide larger amounts of potassium daily might increase the risk of hyperkalemia. Additionally, in vitro research suggests that dulse protein hydrolysates inhibit the activity of ACE. However, these effects have not been demonstrated in humans.
Severity Minor 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 short version on combining dulse seaweed with your Capozide. The captopril part is an ACE inhibitor, and one thing ACE inhibitors do is help your body hold onto potassium. Dulse, like other seaweeds, can carry a fair amount of potassium. So in theory, piling on a lot of dulse could nudge your potassium higher than you want. The good news is the hydrochlorothiazide (the water pill) actually tends to lower potassium, so the two medicines partly balance each other out.

This concern is mostly theoretical and based on the nutrient content, not proven cases. Eating dulse as a food is unlikely to matter, but concentrated supplements are a different story. Since you also have a kidney angle here, check with your pharmacist or doctor before using dulse pills, especially if you ever feel muscle weakness or an odd heartbeat.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Malta D, Arcand J, Ravindran A, Floras V, Allard JP, Newton GE. Adequate intake of potassium does not cause hyperkalemia in hypertensive individuals taking medications that antagonize the renin angiotensin aldosterone system. Am J Clin Nutr 2016 Oct;104(4 PubMed
  2. McGrath BM, Harmon JP, Bishop G. Palmaria palmata (Dulse) as an unusual maritime aetiology of hyperkalemia in a patient with chronic renal failure: a case report. J Med Case Rep. 2010;4:301. PubMed
  3. Furuta T, Miyabe Y, Yasui H, Kinoshita Y, Kishimura H. Angiotensin I converting enzyme inhibitory peptides derived from phycobiliproteins of dulse Palmaria palmata. Mar Drugs. 2016;14(2):32. 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

Dulse Also Interacts With Other Medications

Dulse has 23 moderate, 61 minor known drug interactions in our database — the Captopril, Hydrochlorothiazide one above is one of them. If you take anything else, check it against the full list below.

Moderate 23 Minor 61 No known interaction 2,746 (incl. Captopril, Hydrochlorothiazide)
Taking anything else?

Check Another of Your Medications Against Dulse

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

Everything else you take

See Every Supplement That Interacts With Captopril, Hydrochlorothiazide

This page covers Dulse only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Captopril, 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 Captopril, Hydrochlorothiazide page

“Someone taking Capozide (captopril with hydrochlorothiazide) for blood pressure is often the same person browsing the supplement aisle for heart health, and that is exactly where this list bites. Of the 236 ingredients on file, 10 are rated major, enough to make this a genuine safety review, not trivia.”

Reviewed by 2 · Jul 18, 2026

Open the Captopril, Hydrochlorothiazide interaction page

One more smart check

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

We hold 546 real supplement products containing Dulse, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dulse. Your product may carry other ingredients that interact with Captopril, Hydrochlorothiazide too, on top of Dulse — 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 Dulse and Captopril, 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 Dulse
Top 25%

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

29 days ago today
Medication Captopril, Hydrochlorothiazide
Top half

#789 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 Dulse

What is Dulse?

Dulse
  • Nutritional supplement (iodine, minerals)
  • Source of plant protein
  • General wellness
  • Anti-inflammatory support
  • Thyroid/iodine support

Dulse is a red seaweed eaten as a food in many coastal cultures and is a natural source of iodine, potassium, protein, and antioxidant compounds. As a food it is generally considered safe for most people, but concentrated supplements can deliver large amounts of iodine and potassium, so use caution. Talk to your pharmacist or doctor before using it medicinally, especially if you have thyroid or kidney problems.

Read the full Dulse monograph & all interactions
Medication

About Captopril and Hydrochlorothiazide

What Is Captopril and Hydrochlorothiazide Used For?

Brand names: Capozide, Acezide

Captopril and hydrochlorothiazide tablets are used to treat high blood pressure (hypertension). The two ingredients work together to lower blood pressure more effectively than either one alone.

This combination may be started as initial therapy or substituted when a patient has already been adjusted on both ingredients separately. It is approved for patients with normal kidney function, and is used more cautiously in those with impaired kidney function.

See full Captopril and Hydrochlorothiazide drug information
Keep checking

Other Drugs & Dulse

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

0Major
23Moderate
61Minor
2,745No known interaction
23 Moderate 61 Minor 2,745 No interaction
Moderate

23 interactions

Minor

61 interactions

Showing 60 of 61 minor interactions — see all 61 on the Dulse page.

No interaction 2,745 drugs checked — show the list

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

Showing the 60 most looked-up of 2,745 medications checked with no known interaction — see the full Dulse list.

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

Can you take Dulse with Captopril, Hydrochlorothiazide?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Dulse and Captopril, Hydrochlorothiazide interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Captopril, Hydrochlorothiazide and Dulse?

Our pharmacists answer your medication & supplement questions — free.

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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.