Kelp Ingredients & Drug Interactions
by KAL
What is this page for?
First and foremost: checking Kelp 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
Kelp is a dietary supplement by KAL 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, 893 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Kelp, Iodine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Kelp by KAL
Ask about any prescription or over-the-counter medication and we check it for interactions with Kelp by KAL — 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 Kelp by KAL
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
The active ingredients are iodine and a kelp blend. Iodine is the nutrient that matters most here.
Your thyroid uses it to make its hormones, and the product's listed uses center on iodine's role in thyroid function and radiation exposure. Inactive ingredients listed are cellulose and stearic acid, which are fillers and binders that help form the tablet.
Does it work?
Strong evidence
Iodine's effectiveness ratings are likely effective for radiation exposure and iodine deficiency. It is rated possibly effective for venous leg ulcers, diabetic foot ulcers, and periodontitis (gum disease).
The kelp blend itself has no effectiveness rating in the data we hold, so we can't say how well it works on its own.
How safe is it?
Well-documented data
Iodine is generally well tolerated when taken within the tolerable upper intake level or under medical monitoring. Common side effects include stomach upset, diarrhea, headache, nausea, and a metallic taste.
High doses can cause thyroid problems, so the safety notes say to use only the amount your doctor advises. Pregnancy and lactation data is mixed: one rating is likely safe and another is possibly unsafe, which means the safety data advises against using it unless your doctor directs you.
We hold no pregnancy or breastfeeding data for the kelp blend.
Meds to double-check
Moderate interaction found
Double-check lithium, antithyroid drugs, and amiodarone before taking this product. Each is linked to a Moderate interaction in our data.
Lithium and antithyroid drugs both involve thyroid effects, and amiodarone can raise iodine levels too high. Confirm your exact medications with your doctor or pharmacist.
The bottom line
Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.
This product may be of interest to people looking for iodine support whose doctor has agreed it fits their needs. People who take lithium, antithyroid drugs, or amiodarone, or who have a thyroid condition, should be careful.
Talk it over with your own doctor or pharmacist before starting, especially if you are pregnant or breastfeeding.
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 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
General information
Key facts about Kelp, straight from the product label.
| Brand | KAL |
|---|---|
| Barcode (UPC) | 021245754008 |
| Net contents | 250 Tablet(s) |
| Market status | On market |
| Date entered into DSLD | Feb 23, 2025 |
| DSLD ID | 322916 |
| Product type | Botanical With Nutrients |
| Supplement form | Tablet Or Pill |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Vegetarian, 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 Kelp by KAL, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Iodine | 225 mcg | -- |
| Iodine | 225 mcg | 150% |
| Kelp | 45 mg | -- |
Other ingredients: Cellulose, Stearic Acid
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.
Brand IP Statement(s)
KAL Innovative Quality Since 1932
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
1 Daily
Directions: Use only as directed. Take 1 tablet daily with a meal or glass of water.
Formula
225 mcg Iodine
Discussion: Sea Kelp yields 225 mcg of Iodine.
Formulation
Vegetarian
Iodine is intended to provide nutritive support for the normal health and functioning of the thyroid gland. ActivTab technology guarantees tablets disintegration within 30 minutes according to USP standards.
Vegetarian Formula.
Precautions
Warning: Do not use if safety seal is broken or missing. Keep your licensed health care practitioner informed when using this product.
Keep out of reach of children.
California Residents Warning: Reproductive Harm - www.P65Warnings.ca.gov
Storage
Store in a cool, dry place.
FDA Disclaimer Statement
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.
Seals/Symbols
Clear Quality
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Kelp by KAL 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 Kelp by KAL
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container250 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 & interactionsKelp
Interacts with893 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...
Kelp monograph & interactions- › Iodine
Other (inactive) ingredients: Cellulose, Stearic Acid. These complete the product’s ingredient list but are not active constituents.
Kelp by KAL Drug Interactions
HelloPharmacist Interaction Report
KAL's Kelp tablets can interact with some medications through their iodine content, the only ingredient we could check that has documented interactions.
The most serious severity we list for it is Moderate. Altogether, these interactions span 7 individual medications.
Read the full breakdown — every affected drug type, severity by severity
Iodine may add to the thyroid-slowing effect of lithium, a medication used for mood disorders, and it may change how antithyroid drugs work, both rated Moderate. Combining iodine with amiodarone, a heart rhythm medication, may push iodine levels too high and affect thyroid function, also rated Moderate.
In high doses, iodine can cause either an overactive or an underactive thyroid, depending on your medical history.
The kelp component is listed only as a blend, and we hold no interaction data for it, so we could not check it. Search your exact medications with the search tool on this page, and talk with your own doctor or pharmacist before combining this product with any prescription.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Kelp?
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 Kelp interact with 893 drugs. Click any drug to see the details.
2 of the 2 ingredients in Kelp interact with drugs. Each result below shows which ingredient is responsible. Kelp Iodine
DaprodustatJesduvroq
How Daprodustat interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2c8 (cyp2c8) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2C8 substrates might increase the risk for adverse effects.
Read the full Kelp + Daprodustat interactionDapsoneAczone, Avlosulfon, Dapsone
How Dapsone interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Dapsone interactionDaridorexantQuviviq
How Daridorexant interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Daridorexant interactionDarolutamideNubeqa
How Darolutamide interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Darolutamide interactionDarunavirPrezista
How Darunavir interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Darunavir interactionDarunavir, CobicistatPrezcobix
How Darunavir, Cobicistat interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Darunavir, Cobicistat interactionDarunavir, Cobicistat, Emtricitabine, Tenofovir AlafenamideSymtuza
How Darunavir, Cobicistat, Emtricitabine, Tenofovir Alafenamide interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Darunavir, Cobicistat, Emtricitabine, Tenofovir Alafenamide interactionDarunavir, RitonavirDarunavir, Ritonavir
How Darunavir, Ritonavir interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Darunavir, Ritonavir interactionDasabuvir Sodium, Ombitasvir, Paritaprevir, RitonavirViekira XR
How Dasabuvir Sodium, Ombitasvir, Paritaprevir, Ritonavir interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 2c8 (cyp2c8) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Kelp + Dasabuvir Sodium, Ombitasvir, Paritaprevir, Ritonavir interactionDasatinibPhyrago, Sprycel
How Dasatinib interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Dasatinib interactionDefibrotide SodiumDefitelio
How Defibrotide Sodium interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpAnticoagulant/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 Kelp + Defibrotide Sodium interactionDeflazacortEmflaza
How Deflazacort interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Deflazacort interactionDelavirdine MesylateRescriptor
How Delavirdine Mesylate interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Delavirdine Mesylate interactionDesipramineDesipramine, Norpramin, Pertofrane
How Desipramine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Desipramine interactionDesogestrelCerazette
How Desogestrel interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Desogestrel interactionDesogestrel, Ethinyl EstradiolDesogen, Marvelon, Marvelon 21, Marvelon 28, Mircette, Ortho-Cept +2 more
How Desogestrel, Ethinyl Estradiol interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2c9 (cyp2c9) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2C9 substrates might increase the risk for adverse effects.
Read the full Kelp + Desogestrel, Ethinyl Estradiol interactionDesvenlafaxineKhedezla, Pristiq
How Desvenlafaxine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Desvenlafaxine interactionDeutetrabenazineAustedo
How Deutetrabenazine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Deutetrabenazine interactionDexamethasoneDecadron, Dexone, Dextenza, Dexycu, Hemady, Hexadrol +1 more
How Dexamethasone interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Dexamethasone interactionDexchlorpheniraminePolaramine, Polaramine Repetabs
How Dexchlorpheniramine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Dexchlorpheniramine interactionDexfenfluramineRedux
How Dexfenfluramine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dexfenfluramine interactionDexlansoprazoleDexilant Solutab
How Dexlansoprazole interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome 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 Kelp + Dexlansoprazole interactionDextroamphetamineDexedrine
How Dextroamphetamine interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextroamphetamine interactionDextroamphetamine (patch)Xelstrym
How Dextroamphetamine (patch) interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextroamphetamine (patch) interactionDextroamphetamine SulphateDexedrine Spansule
How Dextroamphetamine Sulphate interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextroamphetamine Sulphate interactionDextromethorphanBenylin Adult, Benylin Pediatric, Hold, Neo Citran Thin Strips Cough, Theraflu Thin Strips Long Acting Cough
How Dextromethorphan interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextromethorphan interactionDextromethorphan HbrVicks Formula 44 Cough Relief
How Dextromethorphan Hbr interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextromethorphan Hbr interactionDextromethorphan Hbr, GuaifenesinPediatric Vicks Formula 44e Cough & Chest Congesti, Vicks Formula 44E Cough & Chest Congestion Relief
How Dextromethorphan Hbr, Guaifenesin interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Kelp + Dextromethorphan Hbr, Guaifenesin interactionDextromethorphan Hbr, Phenylephrine HclVicks Formula 44D Cough & Head Congestion Relief
How Dextromethorphan Hbr, Phenylephrine Hcl interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 2d6 (cyp2d6) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Kelp + Dextromethorphan Hbr, Phenylephrine Hcl interactionDextromethorphan, GuaifenesinAmibid DM, Aquatab DM, Benylin Expectorant, Bidex DM, Fenesin DM, GFN 500 DTMH 30 +17 more
How Dextromethorphan, Guaifenesin interacts with Kelp — through 1 ingredient. Tap an ingredient for the detail:
KelpCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Kelp + Dextromethorphan, Guaifenesin interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Kelp 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.
Kelp
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 Kelp, from the product label.
Kelp by KAL: Common Questions
Does Kelp by KAL interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Is this product safe to take during pregnancy?
What is iodine in this product used for?
What are the most common side effects of iodine?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Kelp is safe with your meds?
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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.
The Full Monographs Behind Kelp’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 893 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
Kelp'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 43 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 28 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.
- Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg 1993;36:453-60.
- Potassium iodide for nuclear exposure. Pharmacist's Letter/Prescriber's Letter 2001;17(12):171214.
- 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.
- Cabezas C, Bustamante B, Holgado W, Begue RE. Treatment of cutaneous sporotrichosis with one daily dose of potassium iodide. Pediatr Infect Dis J 1996;15:352-4. PubMed
- 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
- Yarrington CD, Pearce EN. Dietary iodine in pregnancy and postpartum. Clin Obstet Gynecol 2011;54:459-70. PubMed
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- Crawford, B. A., Cowell, C. T., Emder, P. J., Learoyd, D. L., Chua, E. L., Sinn, J., and Jack, M. M. Iodine toxicity from soy milk and seaweed ingestion is associated with serious thyroid dysfunction. Med J Aust. 10-4-2010;193(7):413-415. PubMed
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