Drug & supplement interaction

Dulse + Colesevelam

Colesevelam brand names: WelChol, Lodalis.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Dulse and Colesevelam in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Colesevelam states a food rule worth keeping to.

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Interaction report

Dulse and Colesevelam

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Colesevelam and Dulse in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Dulse safety at a glance

Dulse overall Use caution Generally safe as a food, but supplements may contain high iodine and potassium and should be used cautiously.
Pregnancy Use caution Food amounts are likely fine, but avoid concentrated supplements due to unpredictable iodine levels and limited safety data.
Breastfeeding Use caution Limited data; excess iodine can pass into breast milk, so avoid supplement doses and check with your doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Colesevelam and Dulse? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Colesevelam

Interactions in our licensed database are recorded against drug classes, not just single drug names. Colesevelam is filed under a single classification — oral drugs. Dulse has documented interactions with 7 drug classes — the most serious being amiodarine (cordarone) (moderate), antithyroid drugs (moderate) and digoxin (lanoxin) (moderate) — and none of Colesevelam’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Dulse Does Interact With Other Medications

Dulse has 23 moderate, 62 minor known drug interactions in our database — Colesevelam isn’t one of them. If you take anything else, check it against the full list below.

Moderate 23 Minor 62 No known interaction 2,745 (incl. Colesevelam)
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.

What to actually watch for

What Colesevelam’s Own FDA Label Lists

This is not an interaction — none of it involves Dulse. These are the most notable effects listed in the ADVERSE REACTIONS section of Colesevelam’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • A bowel blockage Worth acting on
  • Trouble swallowing Worth acting on
  • Low blood sugar Worth acting on
  • A slow heartbeat Worth acting on
  • A heart attack Worth acting on
  • Pancreatitis Worth acting on
  • High blood sugar Worth acting on
  • Seizures Worth acting on
  • Raised blood pressure Worth acting on
  • A higher chance of infection Worth acting on

Showing the 10 most notable of 24 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Colesevelam. Read the label on DailyMed › Where a percentage is shown, it is the share of 2,014 voluntary FDA FAERS reports for Colesevelam that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Dulse’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Dulse side to compare — that is a limit of the record, not a statement that Dulse has no side effects.

How to take them

Some Colesevelam Products Have a Food Rule — Dulse Should Not Break It

At least one FDA label for a product containing Colesevelam says to take it with food. If you take Dulse on an empty stomach out of habit, keep them separate — and take Colesevelam with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Colesevelam products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Colesevelam hydrochloride should be taken as follows ( 2.2 , 2.4 ): Tablets Take 6 tablets once daily or 3 tablets twice daily with a meal and liquid.

From the Dosage and Administration section of the FDA label we read for Colesevelam — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Colesevelam Is Prescribed For, and What Dulse Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Colesevelam is a prescription medicine with approved uses on its FDA label. Dulse is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Colesevelam is prescribed for: Colesevelam is used alongside diet and exercise to reduce high LDL cholesterol (the "bad" cholesterol) in adults with primary hyperlipidemia (high cholesterol). It is also approved to lower LDL cholesterol in boys and girls aged 10–17 who have heterozygous familial hypercholesterolemia (HeFH) — an inherited condition that causes very high cholesterol — when diet and lifestyle changes alone haven't worked. Colesevelam tablets and oral suspension (Welchol and colesevelam hydrochloride products) are also used to improve blood sugar control in adults with type 2 diabetes, as an add-on to diet and exercise. Colesevelam is not for type 1 diabetes or diabetic ketoacidosis.

Dulse has been studied for:

  • Hypercholesterolemia studied, not established Dulse has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Dulse for hypercholesterolemia

    It is unclear if oral dulse is beneficial in patients with hypercholesterolemia.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Colesevelam on your own; if you are taking Dulse for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Dulse or Colesevelam

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 Colesevelam, 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 Colesevelam

This page covers Dulse only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colesevelam page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Colesevelam page

“Colesevelam (WelChol, Lodalis) lowers cholesterol by binding bile acids in your gut, and every one of the 17 supplements on this list can interfere with how oral medicines are absorbed in that same territory. I would treat this list with genuine care, and the place to start is activated charcoal, the only major-rated entry.”

Reviewed by 2 · Jul 18, 2026

Open the Colesevelam 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. Even though Dulse itself has no known interaction with Colesevelam, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Dulse and Colesevelam 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%

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

29 days ago today
Medication Colesevelam
Steady interest

#2,539 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Dulse reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Dulse and Colesevelam records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Palmaria palmata · Palmariaceae · Whole edible thallus (the leafy seaweed fronds) · Dried flakes, whole dried leaf, powder, capsules, and as a food ingredient

An interaction check asks whether these two react with each other — it does not ask whether Dulse is a good idea for someone in your situation. Here is what our Dulse record says about it on its own.

Dulse: dosing

There is no established standardized medicinal dose for dulse. As a food it is eaten in small amounts as flakes, snacks, or a recipe ingredient.If you use a dulse supplement, follow the directions on the product label and do not exceed the recommended amount.

From our Dulse monograph — the full record covers uses, side effects and every documented interaction.

Read the full Dulse monograph & all interactions
Medication

About Colesevelam

What Is Colesevelam Used For?

Brand names: WelChol, Lodalis

Colesevelam is used alongside diet and exercise to reduce high LDL cholesterol (the "bad" cholesterol) in adults with primary hyperlipidemia (high cholesterol). It is also approved to lower LDL cholesterol in boys and girls aged 10–17 who have heterozygous familial hypercholesterolemia (HeFH) — an inherited condition that causes very high cholesterol — when diet and lifestyle changes alone haven't worked.

Colesevelam tablets and oral suspension (Welchol and colesevelam hydrochloride products) are also used to improve blood sugar control in adults with type 2 diabetes, as an add-on to diet and exercise. Colesevelam is not for type 1 diabetes or diabetic ketoacidosis.

Most-Reported Side Effects for Colesevelam

From FAERS, the FDA’s public side-effect reporting system (2,014 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 241 reports
Dyspnea 172 reports
Cough 169 reports
Muscle spasms 163 reports
Nasopharyngitis 150 reports
See full Colesevelam 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
62Minor
2,744No known interaction
23 Moderate 62 Minor 2,744 No interaction
Moderate

23 interactions

Minor

62 interactions

Showing 60 of 62 minor interactions — see all 62 on the Dulse page.

No interaction 2,744 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 2,744 medications checked with no known interaction — see the full Dulse list.

See the full Dulse interactions page
See every supplement checked against Colesevelam, ranked by severity
Evidence & sources

Dulse References

The 5 references that drive our Dulse monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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. Allsopp P, Crowe W, Bahar B, et al. The effect of consuming Palmaria palmata-enriched bread on inflammatory markers, antioxidant status, lipid profile and thyroid function in a randomised placebo-controlled intervention trial in healthy adults. Eur J Nutr PubMed
  3. 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
  4. 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
  5. Takase T, Nakamura A, Miyoshi H, et al. Effects of Palmaria palmata on lipid metabolism and glycemic control in participants with hypercholesterolemia in a randomized double-blind placebo-controlled trial. Phytother Res. 2020.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Dulse and Colesevelam Together: Common Questions

Is it safe to take Dulse with Colesevelam?
We do not list a known interaction between Dulse and Colesevelam. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take Dulse and Colesevelam at the same time of day?
At least one FDA label for a product containing Colesevelam says to take it with food. If you take Dulse on an empty stomach out of habit, keep them separate and take Colesevelam with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Colesevelam products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Are Dulse and Colesevelam used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Dulse in each. That is a conversation for your prescriber, especially if Colesevelam is being adjusted to a target.
How was the Dulse and Colesevelam combination checked?
Interactions in our licensed database are recorded against drug classes. Colesevelam is filed under 1 classification, and Dulse has documented interactions with 7 drug classes — none of Colesevelam's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Dulse interact with any other medications?
Yes. Dulse has 85 documented drug interactions in our database — Colesevelam is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Colesevelam interact with any supplements?
Yes. Colesevelam has documented interactions with 17 supplements in our database — Dulse is not one of them. The Colesevelam interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Dulse monograph Uses, safety profile, and every drug interaction in one place Colesevelam drug information The full plain-English guide to this medication Colesevelam supplement interactions Every supplement checked against Colesevelam, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Colesevelam 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.