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Dietary supplement

Kelp Ingredients & Drug Interactions

by Oregon's Wild Harvest

Capsule Category: Botanical With Nutrients
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Kelp is a dietary supplement by Oregon's Wild Harvest 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, 23 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.

HelloPharmacist Scorecard of Kelp 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

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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product has 2 active ingredients: iodine and kelp (Ascophyllum nodosum), a brown seaweed. Both are sources of dietary iodine, which your body needs to make thyroid hormones and support metabolism.

The capsule also contains pullulan, an inactive ingredient used as a binder.

Does it work?

Strong evidence
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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Iodine and mineral nutrient support.
  • We looked for evidence on: Iodine deficiency, Radiation exposure, Thyroid function, Metabolic support.
  • The strongest evidence on file: Iodine is rated "Likely Effective" for Radiation exposure (Natural Medicines).
  • Also on file: Iodine is rated "Likely Effective" for Iodine deficiency.
  • Also on file: Ascophyllum Nodosum is rated "Insufficient Reliable Evidence To Rate" for Iodine deficiency.

Iodine in this product is likely effective for preventing or treating iodine deficiency and protecting the thyroid after radiation exposure. It may also help with mouth sores and gum disease, though the evidence there is less certain.

Kelp itself, however, has insufficient evidence backing it for blood sugar control, weight management, reflux, iodine deficiency on its own, or inflammatory bowel disease — the data we hold doesn't establish how well it works for those uses.

The evidence, ingredient by ingredient Iodine Ascophyllum Nodosum

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Iodine is well tolerated at normal dietary doses, but high amounts — including from kelp supplements — can trigger thyroid problems. Common side effects from excess iodine include nausea, diarrhea, headache, metallic taste, and goiter (an enlarged thyroid).

Rarely, people can have allergic reactions including hives, swelling, or in severe cases anaphylaxis. Taking too much iodine long-term has also been linked to acne-like skin lesions.

Kelp may accumulate heavy metals depending on where it's harvested, so quality and source matter. In pregnancy, some iodine is essential, but you should use only the amount your doctor recommends and avoid high-dose products.

During breastfeeding, excess iodine passes into breast milk, so medical guidance is important.

Side effects, ingredient by ingredient Iodine Ascophyllum Nodosum

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?
  • 2 of the 2 matched ingredients can interact with medications — Iodine, Ascophyllum Nodosum.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: lithium.
  • For scale: 23 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.

Before you start this product, double-check whether you take antithyroid drugs, amiodarone, lithium, or thyroid hormone replacement — all are documented to interact with the iodine and kelp in this supplement. Moderate severity applies to all of them.

Your thyroid function may need monitoring if you do.

Check your own medication Run your meds through the checker above

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.

If you're iodine-deficient or need thyroid protection after radiation, this kelp product can help — but your doctor or pharmacist should know before you start, especially if you take thyroid, heart, or mood medications. Don't guess about dosing in pregnancy or while nursing; check with your provider.

Run your medications through the checker on this page first.

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 Jun 25, 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 Kelp, straight from the product label.

Brand Oregon's Wild Harvest
Barcode (UPC) 706195004297
Net contents 90 Organic Vegan Capsule(s)
Market status On market
Date entered into DSLD Jun 25, 2025
DSLD ID 331504
Product type Botanical With Nutrients
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 Kelp 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
706195004297
IngredientAmount% DV
Iodine400 mcg270%
Kelp600 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

Actual size

Formulation

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.

Free from: Gluten. dairy and soy allergens.

Organic USDA Organic OTCO Oregon Tilth Certified Organic Certified Organic by Oregon Tilth

Verified Non-GMO Product verified non-GMO by SGS.

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.

Kelp is wild-collected from the ocean; therefore, there is a slight possibility that trace amounts of fish, mollusks, or crustacean shellfish could be present in the product.

Do not exceed recommended dose.

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.

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

USDA Organic OTCO Oregon Tilth Certified Organic Certified Organic by Oregon Tilth Verified Non-GMO

Suggested/Recommended/Usage/Directions

Suggested Use: As an herbal supplement, take one capsule per day with food or as directed by your healthcare professional.

See for yourself

Kelp by Oregon's Wild Harvest label

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

What’s inside

The Ingredients in Kelp by Oregon's Wild Harvest

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container90 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 with
7 drugs
400 mcg per serving Form: Kelp

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 & interactions

Kelp

Interacts with
22 drugs
600 mg per serving

Ascophyllum nodosum (often sold as bladderwrack or brown seaweed) is a nutrient-rich algae that people use for weight, blood sugar, and thyroid suppor...

Kelp monograph & interactions

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

Interaction report

Kelp by Oregon's Wild Harvest Drug Interactions

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 checker
23Drugs
23 Moderate

Ingredients driving the most interactions

Kelp 22
Iodine 7

Each 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.

Kelp3 drug types · 22 drugs

Amiodarone (Cordarone)

Theoretically, combining Ascophyllum nodosum with amiodarone might cause excessively high iodine levels.
Ascophyllum nodosum contains iodine, although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide. 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, Ascophyllum nodosum might alter the effects of antithyroid drugs.
Ascophyllum nodosum contains iodine, although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Ascophyllum nodosum while using antithyroid drugs could alter the effects of the antithyroid drugs.

Likelihood Possible Evidence D
Thyroid Hormone

Due to its iodine content, Ascophyllum nodosum might alter the effects of thyroid hormone.
Ascophyllum nodosum contains iodine, although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Ascophyllum nodosum while using thyroid hormone could alter the effects of thyroid hormone.

Likelihood Possible Evidence D

Iodine3 drug types · 7 drugs

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.

Likelihood Probable Evidence D
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.

Likelihood Probable Evidence D
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.

Likelihood Probable Evidence D
The maker

Brand information

Manufacturer and brand details for Kelp, 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

Kelp by Oregon's Wild Harvest: Common Questions

Does Kelp by Oregon's Wild Harvest interact with any medications?
Yes. Based on its ingredients, Kelp has a known interaction with 23 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Kelp contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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 this safe if I'm pregnant or breastfeeding?
Iodine is essential in pregnancy, but only in the amount your doctor advises — avoid high-dose products like this unless specifically recommended. During breastfeeding, excess iodine passes into breast milk, so follow medical guidance. The kelp ingredient itself should be avoided in both pregnancy and lactation due to high iodine and possible contamination. Talk with your obstetrician or midwife before starting.
Can this cause side effects?
At normal dietary iodine levels, most people tolerate it well. But too much can cause nausea, diarrhea, headache, a metallic taste, or an enlarged thyroid. Long-term excess has been linked to acne-like skin lesions. Rarely, allergic reactions including anaphylaxis can occur. If you develop unusual symptoms, stop and call your pharmacist or doctor.
Does the kelp in this product actually work?
We don't have strong evidence that kelp specifically helps with blood sugar, weight, reflux, iodine deficiency on its own, or gut inflammation — the data is insufficient to say. The iodine ingredient itself is likely effective for iodine deficiency and may help prevent mouth sores and gum disease.
Why do I need to check my thyroid medications?
Both iodine and kelp can change how antithyroid drugs, thyroid hormone, and amiodarone work — and can themselves trigger thyroid problems if you're taking too much. Your prescriber needs to know you're adding an iodine source so they can monitor your thyroid function or adjust your dose if needed.
What's in the capsule besides the active ingredients?
The only inactive ingredient listed is pullulan, a natural binder derived from a fungus. There are no added fillers, colorants, or preservatives noted on the label.
Is there any iodine allergy concern?
True iodine allergy is rare — most "iodine allergies" are actually reactions to seafood proteins or other substances. But some people can be hypersensitive to iodine when taken by mouth, and symptoms can include hives, swelling, fever, or in rare cases anaphylaxis. If you've reacted to iodine-containing drugs or foods before, tell your pharmacist or doctor.

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.

Kelp label
Sources

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.

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 31 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
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
  3. Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg 1993;36:453-60.
  4. Potassium iodide for nuclear exposure. Pharmacist's Letter/Prescriber's Letter 2001;17(12):171214.
  5. 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.
  6. 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
  7. 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
  8. Yarrington CD, Pearce EN. Dietary iodine in pregnancy and postpartum. Clin Obstet Gynecol 2011;54:459-70. PubMed
  9. Goel, S., Mandhani, A., Srivastava, A., Kapoor, R., Gogoi, S., Kumar, A., and Bhandari, M. Is povidone iodine an alternative to silver nitrate for renal pelvic instillation sclerotherapy in chyluria? BJU.Int 2004;94(7):1082-1085. PubMed
  10. Teng, W., Shan, Z., Teng, X., Guan, H., Li, Y., Teng, D., Jin, Y., Yu, X., Fan, C., Chong, W., Yang, F., Dai, H., Yu, Y., Li, J., Chen, Y., Zhao, D., Shi, X., Hu, F., Mao, J., Gu, X., Yang, R., Tong, Y., Wang, W., Gao, T., and Li, C. Effect of iodine int
  11. 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
  12. Ohkuma, M. Molluscum contagiosum treated with iodine solution and salicylic acid plaster. Int J Dermatol. 1990;29(6):443-445. PubMed
  13. Connelly KJ, Boston BA, Pearce EN, Sesser D, Snyder D, Braverman LE, Pino S, LaFranchi SH. Congenital hypothyroidism caused by excess prenatal maternal iodine ingestion. J Pediatr. 2012 Oct;161(4):760-2. PubMed
  14. Kasahara T, Narumi S, Okasora K, Takaya R, Tamai H, Hasegawa T. Delayed onset congenital hypothyroidism in a patient with DUOX2 mutations and maternal iodine excess. Am J Med Genet A. 2013 Jan;161A(1):214-7.
  15. Murcia M, Rebagliato M, Iñiguez C, Lopez-Espinosa MJ, Estarlich M, Plaza B, Barona-Vilar C, Espada M, Vioque J, Ballester F. Effect of iodine supplementation during pregnancy on infant neurodevelopment at 1 year of age. Am J Epidemiol. 2011 Apr 1;173(7):8 PubMed
  16. Sang Z, Wang PP, Yao Z, Shen J, Halfyard B, Tan L, Zhao N, Wu Y, Gao S, Tan J, Liu J, Chen Z, Zhang W. Exploration of the safe upper level of iodine intake in euthyroid Chinese adults: a randomized double-blind trial. Am J Clin Nutr. 2012 Feb;95(2):367-73 PubMed
  17. Speeckaert MM, Speeckaert R, Wierckx K, Delanghe JR, Kaufman JM. Value and pitfalls in iodine fortification and supplementation in the 21st century. Br J Nutr. 2011 Oct;106(7):964-73. PubMed
  18. Yun SE, Kang Y, Bae EJ, Hwang K, Jang HN, Cho HS, Chang SH, Park DJ. Iodine-induced thyrotoxic hypokalemic paralysis after ingestion of Salicornia herbace. Ren Fail. 2014 Apr;36(3):461-3.
  19. Iodine Hypersensitivity. Pharmacist's Letter/Prescriber's Letter 2011; 27(5):270504.
  20. Hammel JA, Selby JC. Pustular eruption in a patient with cancer treated with complementary and alternative medicine. JAMA Dermatology 2017 October; E1. doi: 10.1001/jamadermatol.2017.3749. [Epub ahead of print] PubMed
  21. Gil GS, Smith BW, Guerra JR, Williams WT. Acute Delirium in a Hypothyroid Patient Precipitated by Iodine Supplements Use. Am J Ther. 2018;25(6):e717-e718. PubMed
  22. Hamby T, Kunnel N, Dallas JS, Wilson DP. Maternal iodine excess: an uncommon cause of acquired neonatal hypothyroidism. J Pediatr Endocrinol Metab. 2018;31(9):1061-1064. PubMed
  23. Censi S, Watutantrige-Fernando S, Groccia G, et al. The Effects of Iodine Supplementation in Pregnancy on Iodine Status, Thyroglobulin Levels and Thyroid Function Parameters: Results from a Randomized Controlled Clinical Trial in a Mild-to-Moderate Iodine
  24. Rovner MS, Wolf BJ, Rubin M, et al. Instillation of 5% Povidone-Iodine Ophthalmic Drops Decreases the Respiratory Rate in Children Undergoing Strabismus Surgery: A Randomized Controlled Trial. J Pediatr Ophthalmol Strabismus. 2019;56(6):378-382. PubMed
  25. Guenezan J, Garcia M, Strasters D, et al. Povidone Iodine Mouthwash, Gargle, and Nasal Spray to Reduce Nasopharyngeal Viral Load in Patients With COVID-19: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg. 2021;147(4):400-401. PubMed
  26. Li F, Wan S, Zhang L, et al. A Meta-Analysis of the Effect of Iodine Excess on the Intellectual Development of Children in Areas with High Iodine Levels in their Drinking Water. Biol Trace Elem Res 2022;200(4):1580-1590. PubMed

See these in context on the Iodine monograph →

Ascophyllum Nodosum 5 references
  1. 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.
  2. 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
  3. Combet E, Ma ZF, Cousins F, et al. Low-level seaweed supplementation improves iodine status in iodine-insufficient women. Br J Nutr 2014;112:753-61. PubMed
  4. Simmons-Boyce JL, Purcell SL, Nelson CM, MacKinnon SL. Dietary Ascophyllum nodosum increases urinary excretion of tricarboxylic acid cycle intermediates in male Sprague-dawley rats. J Nutr 2009;139:1487-94. PubMed
  5. Sorge US, Henriksen M, Bastan A, et al. Short communication: Iodine concentrations in serum, milk, and tears after feeding Ascophyllum nodosum to dairy cows-A pilot study. J Dairy Sci 2016;99:8472-6. PubMed

See these in context on the Ascophyllum Nodosum 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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