Drug & supplement interaction

Dulse + Captopril

Captopril brand names: Capoten, Acepril.

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

Dulse has a minor interaction with Captopril. 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

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

Minor

ACE INHIBITORS (ACEIs)

Why this applies to Captopril

Captopril 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 simple version. Captopril works by relaxing your blood vessels, and one side effect of that is your body holds onto a bit more potassium. Dulse, a red seaweed, is naturally loaded with potassium. So if you eat a lot of it, especially in concentrated supplement form, the two together could push your potassium a little too high (called hyperkalemia). That can show up as muscle weakness, tingling, or in serious cases an irregular heartbeat.

The good news: this is mostly a theoretical concern based on how things work on paper, not proven in people. Eating dulse as an occasional food is unlikely to be a problem for most folks. If you have kidney trouble or take other potassium-raising meds, or you're using a daily dulse supplement, check with your pharmacist or doctor first.

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 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)
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.

From our Q&A

Questions About Dulse or Captopril

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

This page covers Dulse only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Captopril page lists 166 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 Siberian Cocklebur (major).

By severity: 6 major · 136 moderate · 24 minor.

From our pharmacist’s overview on the Captopril page

“Anyone taking captopril (Capoten), an ACE inhibitor for high blood pressure and heart failure, should treat this list with genuine care rather than a quick skim. Most of the ingredients here act on blood pressure itself, some dropping it lower than intended and others, tyramine among them, pushing it back up and working against the med…”

Reviewed by 2 · Jul 18, 2026

Open the Captopril 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 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 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%

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

29 days ago today
Medication Captopril
Top half

#902 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

What Is Captopril Used For?

Brand names: Capoten, Acepril

Captopril tablets lower high blood pressure. They also treat heart failure, usually along with a diuretic (water pill) and digitalis.

Captopril tablets are also used after a heart attack in stable patients whose heart pumps weakly (left ventricular dysfunction). In people with type 1 diabetes and eye damage (retinopathy), they treat diabetic nephropathy (diabetes-related kidney disease with protein in the urine).

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

Can you take Dulse with Captopril?
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 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 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.