Bladderwrack Leaves Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Bladderwrack Leaves 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
Bladderwrack Leaves is a dietary supplement by Swanson Superior Herbs with 2 active ingredients. Its ingredients are commonly taken for preventing iodine deficiency, supporting thyroid hormone production, general energy and metabolism support.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 leaf extract, Iodine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Bladderwrack Leaves by Swanson Superior Herbs
Ask about any prescription or over-the-counter medication and we check it for interactions with Bladderwrack Leaves by Swanson Superior Herbs — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Bladderwrack Leaves by Swanson Superior Herbs
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.
What’s inside
Full disclosure
This product contains 2 active ingredients: iodine and bladderwrack leaf extract (Fucus vesiculosus), a seaweed rich in iodine. The capsule also contains several inactive ingredients — microcrystalline cellulose, gelatin, calcium palmitate, maltodextrin, and silica — which are fillers and binders.
Does it work?
Strong evidence
Iodine in this product is likely effective for preventing iodine deficiency and protecting the thyroid and body tissues from radiation exposure. It's possibly effective for oral mucositis (mouth sores) and periodontitis (gum disease).
For bladderwrack leaf extract, the evidence we have doesn't establish its effectiveness for aging skin, heart disease, constipation, diarrhea, or upset digestion — more reliable research is needed.
How safe is it?
Well-documented data
Iodine is well tolerated in normal dietary amounts, but high doses can cause thyroid problems including goiter and abnormal thyroid function. Most common side effects include nausea, diarrhea, headache, metallic taste, and nasal discharge.
Rarely, some people experience serious allergic reactions. Taking chronic high doses of iodine has been linked to acneform skin lesions.
Bladderwrack extract may be unsafe orally because of its variable, high iodine content and potential to concentrate heavy metals; it can cause goiter, thyroid dysfunction, and rarely thyroid cancer. For pregnancy: iodine is likely safe in amounts your doctor advises, but high-dose products should be avoided.
Bladderwrack extract is possibly unsafe in pregnancy because of excess iodine. For breastfeeding: iodine is needed in small amounts but excess passes into breast milk, so follow medical guidance.
Bladderwrack extract should be avoided while nursing because iodine can affect the baby's thyroid.
Meds to double-check
Moderate interaction found
Before you start, check with your pharmacist if you take lithium, antithyroid drugs (like methimazole or propylthiouracil), amiodarone, or thyroid hormone replacement — all have moderate interactions with this product's iodine content. If you take medications processed through your liver's CYP2D6, CYP2C9, or CYP3A4 systems (including many heart, blood pressure, and mood drugs), or blood thinners and antiplatelet drugs, those should be reviewed as well, though human evidence is limited.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
This product is a high-iodine supplement that works best for people with confirmed iodine deficiency under medical supervision. If you take lithium, thyroid medications, amiodarone, or thyroid hormone replacement, talk to your pharmacist before starting — thyroid function monitoring is essential.
Avoid this product during pregnancy and breastfeeding. Check your medications with the tool below.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 21, 2017.
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
General information
Key facts about Bladderwrack Leaves, straight from the product label.
| Brand | Swanson Superior Herbs |
|---|---|
| Barcode (UPC) | 087614141749 |
| Net contents | 60 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Sep 21, 2017 |
| DSLD ID | 79007 |
| Product type | Other Combinations |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years) |
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 Leaves by Swanson Superior Herbs, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Iodine | 150 mcg | 100% |
| Bladderwrack leaf extract | 75 mg | -- |
Other ingredients: Microcrystalline Cellulose, Gelatin, Calcium Palmitate, Maltodextrin, Silica
Tap any ingredient to jump to its full detail below.
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.
FDA Statement of Identity
Standardized Herbal Supplement
Seals/Symbols
Guaranteed Purity & Potency
General Statements
Supports thyroid health
To reorder, call toll free 1-800-437-4148 or visit our website at www.swansonvitamins.com
FDA Disclaimer Statement
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Precautions
Do not use if seal is broken.
Keep out of reach of children.
Warning: Consult your healthcare provider before use if you are pregnant or nursing, taking prescription medication or if you have a medical condition.
Do not exceed recommended dosage.
Storage
Store in a cool, dry place.
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take one capsule per day with water.
General
SWH174 Rev 1 03 30 17
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Bladderwrack Leaves by Swanson Superior Herbs label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Bladderwrack Leaves by Swanson Superior Herbs
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.
Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.
Iodine
Interacts with7 drugs
Iodine is an essential mineral your body needs to make thyroid hormones, and most people get enough from iodized salt, dairy, and seafood. Supplements...
Iodine monograph & interactionsBladderwrack leaf extract
Interacts with891 drugs
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 leaf extract monograph & interactionsOther (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Calcium Palmitate, Maltodextrin, Silica. These complete the product’s ingredient list but are not active constituents.
Bladderwrack Leaves by Swanson Superior Herbs Drug Interactions
HelloPharmacist Interaction Report
Bladderwrack Leaves by Swanson Superior Herbs contains two active ingredients — iodine and bladderwrack leaf extract (Fucus vesiculosus) — both of which are high in iodine and interact with several medication classes.
The most serious concern is with lithium, a mood stabilizer: both ingredients can add to lithium's thyroid-suppressing effects and have been linked to thyroid problems in patients taking them together. You'll need thyroid monitoring if you take lithium.
Read the full breakdown — every affected drug type, severity by severity
Both ingredients also interact with antithyroid drugs and amiodarone (a heart rhythm medication), potentially altering how these drugs work or causing excessive iodine buildup that affects your thyroid. Additionally, the bladderwrack extract may theoretically interact with medications broken down by your liver's CYP2D6, CYP2C9, and CYP3A4 enzymes — including many heart and blood pressure drugs, some antidepressants, and others — though this has not been confirmed in human studies.
It may also theoretically increase bleeding risk with blood thinners and antiplatelet drugs, though clinical evidence is limited. The bladderwrack extract also interacts with thyroid hormone replacement.
Altogether, these interactions span 892 individual medications. Run your exact medications through the checker on this page before you start.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Bladderwrack Leaves?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Bladderwrack Leaves interact with 891 drugs. Click any drug to see the details.
2 of the 2 ingredients in Bladderwrack Leaves interact with drugs. Each result below shows which ingredient is responsible. Bladderwrack leaf extract Iodine
AmiodaroneCordarone, Pacerone
How Amiodarone interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 2c8 (cyp2c8) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2C8 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Amiodarone interactionIodineAmiodarone (cordarone) Moderate
Interaction Summary
Combining iodine with amiodarone might cause excessively high iodine levels.
Read the full Iodine + Amiodarone interactionCarbimazoleNeo-Mercazole
How Carbimazole interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
IodineAntithyroid Drugs Moderate
Interaction Summary
Iodine might alter the effects of antithyroid drugs.
Read the full Iodine + Carbimazole interactionBladderwrack Leaf ExtractAntithyroid Drugs Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Read the full Bladderwrack Leaf Extract + Carbimazole interactionConjugated EstrogensCenestin, Enjuvia, Premarin, Premarin Vaginal Cream
How Conjugated Estrogens interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates, Thyroid Hormone Moderate
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Conjugated Estrogens interactionDesiccated Thyroid ExtractWesthroid, WP Thyroid
How Desiccated Thyroid Extract interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Desiccated Thyroid Extract interactionDesiccated Thyroid Extract (prescription Drug)Nature-Throid, Thyrar
How Desiccated Thyroid Extract (prescription Drug) interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Desiccated Thyroid Extract (prescription Drug) interactionDextrothyroxineCholoxin
How Dextrothyroxine interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Dextrothyroxine interactionHuman Chorionic Gonadotropin (hcg)Pregnyl
How Human Chorionic Gonadotropin (hcg) interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Human Chorionic Gonadotropin (hcg) interactionLevothyroxineEltroxin, Estre, Euthyrox, Levo-T, Levolet, Levothroid +5 more
How Levothyroxine interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Levothyroxine interactionLevothyroxine SodiumErmez, Thyquidity, Tirosint-Sol
How Levothyroxine Sodium interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Levothyroxine Sodium interactionLevothyroxine, LiothyronineArmour Thyroid
How Levothyroxine, Liothyronine interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Levothyroxine, Liothyronine interactionLiothyronineCytomel
How Liothyronine interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Liothyronine interactionLiotrixEuthroid 1, Euthroid 1/2, Euthroid 3
How Liotrix interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Liotrix interactionLiotrix, T4/t3Euthroid 2
How Liotrix, T4/t3 interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Liotrix, T4/t3 interactionLithium Carbonate (prescription Drug)Eskalith, Lithium Carbonate
How Lithium Carbonate (prescription Drug) interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
IodineLithium Moderate
Interaction Summary
Combining iodine with lithium might have additive hypothyroid effects.
Read the full Iodine + Lithium Carbonate (prescription Drug) interactionBladderwrack Leaf ExtractLithium Moderate
Interaction Summary
Concomitant use of Fucus vesiculosus and lithium has resulted in hyperthyroidism.
Read the full Bladderwrack Leaf Extract + Lithium Carbonate (prescription Drug) interactionMenotropinsMenopur, Repronex
How Menotropins interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Menotropins interactionMethenamine MandelateMandelamine, Methimazole
How Methenamine Mandelate interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
IodineAntithyroid Drugs Moderate
Interaction Summary
Iodine might alter the effects of antithyroid drugs.
Read the full Iodine + Methenamine Mandelate interactionBladderwrack Leaf ExtractAntithyroid Drugs Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Read the full Bladderwrack Leaf Extract + Methenamine Mandelate interactionMethimazoleTapazole
How Methimazole interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractAntithyroid Drugs Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Read the full Bladderwrack Leaf Extract + Methimazole interactionIodineAntithyroid Drugs Moderate
Interaction Summary
Iodine might alter the effects of antithyroid drugs.
Read the full Iodine + Methimazole interactionOspemifeneOsphena
How Ospemifene interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates, Thyroid Hormone Moderate
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Ospemifene interactionPotassium Iodide (prescription Drug)Thyro-Block
How Potassium Iodide (prescription Drug) interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
IodineAntithyroid Drugs Moderate
Interaction Summary
Iodine might alter the effects of antithyroid drugs.
Read the full Iodine + Potassium Iodide (prescription Drug) interactionBladderwrack Leaf ExtractAntithyroid Drugs Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Read the full Bladderwrack Leaf Extract + Potassium Iodide (prescription Drug) interactionPropylthiouracil, PtuPropylthiouracil
How Propylthiouracil, Ptu interacts with Bladderwrack Leaves — through 2 ingredients. Tap an ingredient for the detail:
IodineAntithyroid Drugs Moderate
Interaction Summary
Iodine might alter the effects of antithyroid drugs.
Read the full Iodine + Propylthiouracil, Ptu interactionBladderwrack Leaf ExtractAntithyroid Drugs Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Read the full Bladderwrack Leaf Extract + Propylthiouracil, Ptu interactionTestosterone UndecanoateAndriol, Aveed, Jatenzo, Kyzatrex
How Testosterone Undecanoate interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates, Thyroid Hormone Moderate
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Testosterone Undecanoate interactionThyroglobulinProloid
How Thyroglobulin interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Thyroglobulin interactionThyroid HormoneEtwon
How Thyroid Hormone interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Leaf Extract + Thyroid Hormone interactionAdo-trastuzumab EmtansineKadcyla
How Ado-trastuzumab Emtansine interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Ado-trastuzumab Emtansine interactionAbciximabReoPro
How Abciximab interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractAnticoagulant/antiplatelet Drugs Minor
Interaction Summary
Theoretically, taking Fucus vesiculosus with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.
Read the full Bladderwrack Leaf Extract + Abciximab interactionAbemaciclibVerzenio
How Abemaciclib interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Abemaciclib interactionAbiraterone
How Abiraterone interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Abiraterone interactionAbiraterone AcetateYonsa, Zytiga
How Abiraterone Acetate interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Abiraterone Acetate interactionAbrocitinibCibinqo
How Abrocitinib interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractAnticoagulant/antiplatelet Drugs, Cytochrome P450 2c9 (cyp2c9) Substrates Minor
Interaction Summary
Theoretically, taking Fucus vesiculosus with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.
Read the full Bladderwrack Leaf Extract + Abrocitinib interactionAcalabrutinibCalquence
How Acalabrutinib interacts with Bladderwrack Leaves — through 1 ingredient. Tap an ingredient for the detail:
Bladderwrack Leaf ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Leaf Extract + Acalabrutinib interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Bladderwrack Leaves with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.
Bladderwrack leaf extract
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.
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.
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.
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.
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.
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.
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.
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.
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.
Iodine
Amiodarone (Cordarone)
Combining iodine with amiodarone might cause excessively high iodine levels.
Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use with iodine might increase the risk of having excessive iodine levels and adversely affecting thyroid function. Monitor thyroid function.
Antithyroid Drugs
Iodine might alter the effects of antithyroid drugs.
Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking iodine while using antithyroid drugs could alter the effects of the antithyroid drugs.
Lithium
Combining iodine with lithium might have additive hypothyroid effects.
Lithium can inhibit thyroid function. Several case reports suggest that concomitant use of lithium and potassium iodide can reduce thyroid function in otherwise healthy adults. Monitor thyroid function.
Brand information
Manufacturer and brand details for Bladderwrack Leaves, from the product label.
Swanson Superior Herbs
See all Swanson Superior Herbs products- Name
- Swanson Health Products
- City
- Fargo
- State
- ND
- ZipCode
- 58104
- Phone Number
- 1-800-437-4148
- Web Address
- www.swansonvitamins.com
Bladderwrack Leaves by Swanson Superior Herbs: Common Questions
Does Bladderwrack Leaves by Swanson Superior Herbs interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Is bladderwrack safe to take long-term?
Can I take this if I have thyroid disease?
What side effects might I notice from the iodine?
Does this product have any fillers?
Will this help with weight loss?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Bladderwrack Leaves is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind Bladderwrack Leaves’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Iodine
Interacts with 7 drugsIodine is an essential mineral your body needs to make thyroid hormones, and most people get enough from iodized salt, dairy, and seafood. Supplements help when you are truly deficient, but...
Read the full Iodine monograph → Herb & supplement monographFucus Vesiculosus
Interacts with 891 drugsFucus 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 & How We Checked
Bladderwrack Leaves'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 41 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.
Iodine 26 references
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
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