Mineral
Kelp
Also known as: Sea Kelp, Kelp Powder, Seaweed, Laminaria
Kelp is a natural source of iodine and trace minerals, supporting thyroid function and providing marine-derived nutrients.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Kelp product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Thorne Daily Greens Plus | 79 B+ | $0.83 |
| 2 | New Chapter Perfect Postnatal Multivitamin | 78 B+ | $0.39 |
| 3 | Terra Origin Healthy Stress Relief | 78 B+ | $0.67 |
| 4 | NOW Foods Liquid Multi - Tropical Orange | 76 B+ | $0.69 |
| 5 | Zhou Nutrition Thyroid Support | 74 B+ | $0.71 |
| 6 | BulkSupplements Kelp Extract Powder | 71 B | $0.03 |
| 7 | Trace Minerals Electrolyte Stamina | 67 B | $1.00 |
| 8 | Terra Origin Digestive Enzyme Capsules | 65 B- | $0.33 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much Kelp should I take?
The typical range is 150-500 mcg iodine equivalent. Monitor thyroid with long-term use
When should I take Kelp?
With meals. Yes.
Which form of Kelp is best?
Standardized iodine — Consistent iodine content. Other forms in the catalog: Organic kelp, Whole thallus, Powder.
Is Kelp safe?
Commonly reported: Metallic taste, GI upset. Serious warnings: Excess can affect thyroid, Heavy metal contamination risk. No direct concerns
Which Kelp supplement scores highest?
Thorne Daily Greens Plus, at 79/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Daily target & upper limit
150 mcg / day · UL 1100 mcgKelp has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
Kelp dosage reference →Primary uses
- Thyroid support
- Iodine supplementation
- Trace minerals
- Metabolic support
How it works
- Provides bioavailable iodine
- Supports thyroid hormone synthesis
- Trace mineral nutrition
Dosage
- Typical range
- 150-500 mcg iodine equivalent
- Timing
- With meals
- With food
- Yes
- Duration
- Monitor thyroid with long-term use
- Special populations
- Iodine-deficient populations
Forms
- Standardized iodine· 95/100
- Organic kelp· 90/100
- Whole thallus· 85/100
- Powder· 80/100
Safety
Common side effects
- Metallic taste
- GI upset
Contraindications
- Hyperthyroidism
- Hashimotos without guidance
Products containing Kelp
Top-scoring supplements in our catalog that list Kelp on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Known interactions
Evidence notes
Well-established iodine source, thyroid support
Grade B: Some human trials support key claims; further confirmation needed.
Related in Mineral
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.