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Dietary supplement

Bladderwrack Ingredients & Drug Interactions

by Oregon's Wild Harvest

Bladderwrack label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Bladderwrack against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Bladderwrack is a dietary supplement by Oregon's Wild Harvest with 1 active ingredient. Its ingredients are commonly taken for thyroid support, iodine source, weight management.Based on those ingredients, 891 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bladderwrack. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Bladderwrack by Oregon's Wild Harvest

Ask about any prescription or over-the-counter medication and we check it for interactions with Bladderwrack by Oregon's Wild Harvest — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Bladderwrack by Oregon's Wild Harvest

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Oregon's Wild Harvest Bladderwrack is a single-ingredient supplement—just bladderwrack (Fucus vesiculosus) in a capsule form. Bladderwrack is a brown seaweed that's high in iodine and other minerals.

The inactive ingredient is pullulan, a capsule binder.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Fucus Vesiculosus product and its label doesn't state a use — see Fucus Vesiculosus's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold doesn't establish that bladderwrack works for any of its proposed uses. Aging skin, heart disease, constipation, diarrhea, and indigestion all carry a rating of insufficient reliable evidence to rate effectiveness.

That doesn't mean it doesn't work—it means the data supporting it isn't solid enough to say.

The evidence, ingredient by ingredient Fucus Vesiculosus

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Bladderwrack is a concern orally because of its iodine content. The most common side effects are thyroid-related: goiter (enlarged thyroid), overactive thyroid, and underactive thyroid.

Rarely, thyroid cancer has been reported. One case showed heart palpitations and fainting in a young adult taking a combination product that included bladderwrack.

Pregnancy and breastfeeding are contraindicated. The data advises against use in pregnancy because excess iodine and possible heavy metal content in the plant can harm your baby.

During breastfeeding, iodine passes into milk and may disrupt the baby's thyroid, so avoid it then too.

Side effects, ingredient by ingredient Fucus Vesiculosus

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Fucus Vesiculosus.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; lithium.
  • For scale: 892 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take lithium, antithyroid drugs, thyroid hormone, or amiodarone, double-check with your pharmacist first—all are moderate-severity concerns with bladderwrack's high iodine content. Blood thinners (anticoagulants and antiplatelet drugs) carry a minor theoretical risk.

So do certain enzyme substrates your liver uses to process drugs (CYP2D6, CYP2C9, and CYP3A4 substrates), though these haven't been reported in real people.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Bladderwrack is best avoided if you take lithium, any thyroid medication, or amiodarone. If you're pregnant or breastfeeding, don't use it—the iodine and potential heavy metals are unsafe for your baby.

Even if none of those apply, the evidence for what it's supposed to do isn't there yet. Talk to your pharmacist before you start.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Feb 23, 2025.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Bladderwrack, straight from the product label.

Brand Oregon's Wild Harvest
Barcode (UPC) 706195000732
Net contents 90 Organic Vegan Capsule(s)
Market status On market
Date entered into DSLD Feb 23, 2025
DSLD ID 323202
Product type Botanical
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Organic, Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Bladderwrack by Oregon's Wild Harvest, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
90
UPC/BARCODE
706195000732
IngredientAmount% DV
Bladderwrack600 mg--

Other ingredients: Pullulan

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Organic to our roots As certified organic farmers since 1994, our regenerative practices heal the land and water and sequester carbon from the atmosphere, while ensuring that pure, potent herbal medicine is available today and for future generations. Peace.

Actual size

Formulation

Free from: Gluten, dairy and soy allergens.

Organic

GF (Gluten free) Verified Non-GMO Product verified non-GMO by SGS.

Certified organic by Oregon Tilth

Precautions

Caution: Keep out of reach of children.

If taking medication consult with a healthcare professional before use. Do not take if pregnant or nursing.

Discontinue use if unusual symptoms occur.

Do not exceed recommended dose.

Brand IP Statement(s)

Oregon's Wild Harvest Herbal Supplement Family Farm Since 1994

FDA Statement of Identity

Herbal Supplement

Formula

Natural source of iodine

Seals/Symbols

Verified Non-GMO USDA Organic

Oregon Tilth Certified Organic (OTCO)

Suggested/Recommended/Usage/Directions

Suggested use: As an herbal supplement, take one capsule daily or as directed by your healthcare professional. Do not exceed recommended dose.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Bladderwrack by Oregon's Wild Harvest label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Bladderwrack label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Bladderwrack by Oregon's Wild Harvest

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container90 Amounts shown are per serving.

Bladderwrack

Interacts with
891 drugs
600 mg per serving

Fucus vesiculosus (bladderwrack) is a brown seaweed rich in iodine that has been used traditionally for thyroid concerns, weight, and skin. There is l...

Bladderwrack monograph & interactions

Other (inactive) ingredients: Pullulan. These complete the product’s ingredient list but are not active constituents.

Interaction report

Bladderwrack by Oregon's Wild Harvest Drug Interactions

Want to check YOUR meds against Bladderwrack?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
891Drugs
23 Moderate 868 Minor

Ingredients driving the most interactions

Bladderwrack 891

Individual Drug Interactions

The ingredients in Bladderwrack interact with 891 drugs. Click any drug to see the details.

1 of the 1 ingredient in Bladderwrack interact with drugs. Each result below shows which ingredient is responsible. Bladderwrack

Each ingredient & the kinds of drugs it affects

For each ingredient in Bladderwrack with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Bladderwrack9 drug types · 891 drugs

Amiodarone (Cordarone)

Theoretically, combining Fucus vesiculosus with amiodarone might cause excessively high iodine levels.
Fucus vesiculosus contains high concentrations of iodine. Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use might increase the risk of having excessive iodine levels and adversely affecting thyroid function. Monitor thyroid function.

Likelihood Probable Evidence D
Antithyroid Drugs

Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Fucus vesiculosus contains high concentrations of iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using antithyroid drugs could alter the effects of the antithyroid drugs.

Likelihood Possible Evidence D
Lithium

Concomitant use of Fucus vesiculosus and lithium has resulted in hyperthyroidism.
There is a case of hyperthyroidism occurring in a patient taking Fucus vesiculosus and lithium. Monitor thyroid hormones closely in patients taking lithium and Fucus vesiculosus concomitantly.

Likelihood Possible Evidence D
Thyroid Hormone

Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Fucus vesiculosus contains high concentrations of iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using thyroid hormone could alter the effects of thyroid hormone.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, taking Fucus vesiculosus with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.
In vitro evidence suggests that a constituent of Fucus vesiculosus, known as fucoidan, has anticoagulant effects. However, in clinical research, fucoidan does not seem to have significant anticoagulant activity when taken orally, possibly due to poor absorption.

Likelihood Unlikely Evidence D
Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, concomitant use of Fucus vesiculosus with CYP2C8 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C8. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, concomitant use of Fucus vesiculosus with CYP2C9 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C9. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, both inhibits and induces CYP2D6. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP3A4. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Bladderwrack full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Bladderwrack, from the product label.

Oregon's Wild Harvest

See all Oregon's Wild Harvest products
Name
Oregon's Wild Harvest
City
Redmond
State
OR
ZipCode
97756
Phone Number
800-316-6869
Web Address
oregonswildharvest.com
Pharmacist Counseling Corner

Bladderwrack by Oregon's Wild Harvest: Common Questions

Does Bladderwrack by Oregon's Wild Harvest interact with any medications?
Yes. Based on its ingredients, Bladderwrack has a known interaction with 891 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Bladderwrack contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is bladderwrack safe to take if I'm pregnant or nursing?
No. The safety data advises against it in pregnancy because of excess iodine and possible heavy metal content. During breastfeeding, iodine passes into breast milk and may affect your baby's thyroid. Talk to your doctor about safer options.
What are the main side effects?
The most common side effects are thyroid-related: goiter, overactive thyroid, and underactive thyroid. These happen because bladderwrack is very high in iodine. Rarely, heart palpitations and fainting have been reported.
Does bladderwrack actually work for skin or digestion?
The evidence we hold doesn't establish that it works for aging skin, heart disease, constipation, diarrhea, or indigestion. The data just isn't solid enough to say either way.
Why is iodine in bladderwrack a problem?
Bladderwrack contains very high concentrations of iodine. Too much iodine can disrupt your thyroid and cause it to work either too fast or too slow. It's especially risky if you take lithium or thyroid medications, because it can make those drugs less effective or cause serious thyroid problems.
Can I take this with my blood thinner?
There's a minor theoretical risk. Lab evidence suggests bladderwrack might have blood-thinning effects, which could increase bruising and bleeding when combined with anticoagulants or antiplatelet drugs. It hasn't been reported in people, but check with your pharmacist before starting.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Bladderwrack label
Go deeper

The Full Monographs Behind Bladderwrack’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Fucus Vesiculosus

Interacts with 891 drugs

Fucus vesiculosus (bladderwrack) is a brown seaweed rich in iodine that has been used traditionally for thyroid concerns, weight, and skin. There is little solid human evidence to support mo...

Read the full Fucus Vesiculosus monograph →
Sources

Sources & How We Checked

Bladderwrack's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 15 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Fucus Vesiculosus 15 references
  1. Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  3. Phaneuf D, Cote I, Dumas P, et al. Evaluation of the contamination of marine algae (Seaweed) from the St. Lawrence River and likely to be consumed by humans. Environ Res 1999;80:S175-S182. PubMed
  4. Durig J, Bruhn T, Zurborn KH, et al. Anticoagulant fucoidan fractions from Fucus vesiculosus induce platelet activation in vitro. Thromb Res 1997;85:479-91. PubMed
  5. Conz PA, La Greca G, Benedetti P, et al. Fucus vesiculosus: a nephrotoxic alga? Nephrol Dial Transplant 1998;13:526-7.
  6. Ohye H, Fukata S, Kanoh M, et al. Thyrotoxicosis caused by weight-reducing herbal medicines. Arch Intern Med 2005;165:831-4. PubMed
  7. Okamura K, Inoue K, Omae T. A case of Hashimoto's thyroiditis with thyroid immunological abnormality manifested after habitual ingestion of seaweed. Acta Endocrinol (Copenh) 1978;88:703-12. PubMed
  8. Agarwal SC, Crook JR, Pepper CB. Herbal remedies -- how safe are they? A case report of polymorphic ventricular tachycardia/ventricular fibrillation induced by herbal medication used for obesity. Int J Cardiol 2006;106:260-1. PubMed
  9. Sterling JB, Heymann WR. Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol 2000;43:691-7. PubMed
  10. Catania, M. A., Oteri, A., Caiello, P., Russo, A., Salvo, F., Giustini, E. S., Caputi, A. P., and Polimeni, G. Hemorrhagic cystitis induced by an herbal mixture. South.Med.J. 2010;103(1):90-92. PubMed
  11. Cumashi, A., Ushakova, N. A., Preobrazhenskaya, M. E., D'Incecco, A., Piccoli, A., Totani, L., Tinari, N., Morozevich, G. E., Berman, A. E., Bilan, M. I., Usov, A. I., Ustyuzhanina, N. E., Grachev, A. A., Sanderson, C. J., Kelly, M., Rabinovich, G. A., I
  12. Irhimeh, M. R., Fitton, J. H., and Lowenthal, R. M. Pilot clinical study to evaluate the anticoagulant activity of fucoidan. Blood Coagul.Fibrinolysis 2009;20(7):607-610. PubMed
  13. Arbaizar, B. and Llorca, J. [Fucus vesiculosus induced hyperthyroidism in a patient undergoing concomitant treatment with lithium]. Actas Esp.Psiquiatr. 2011;39(6):401-403.
  14. Church FC, Meade JB, Treanor RE, and et al. Antithrombin activity of fucoidan. The interaction of fucoidan with heparin cofactor II, antithrombin III, and thrombin. J Biol Chem 2-25-1989;264(6):3618-3623. DOI
  15. Mathew L, Burney M, Gaikwad A, et al. Preclinical evaluation of safety of fucoidan extracts from Undaria pinnatifida and Fucus vesiculosus for use in cancer treatment. Integr Cancer Ther 2017;16(4):572-84.

See these in context on the Fucus Vesiculosus monograph →

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

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