Mineral
Iodine
Also known as: I, Iodide, Potassium iodide, Sodium iodide
Essential trace mineral for thyroid hormone production. Critical for metabolism, brain development, and energy.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Iodine product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Pure Encapsulations Iodine (potassium iodide) | 92 A | $0.17 |
| 2 | Performance Lab Iodine | 92 A | $0.97 |
| 3 | NOW Foods Kelp | 91 A | $0.05 |
| 4 | Thorne Thyroid Health Complex | 90 A | $0.33 |
| 5 | Pure Encapsulations Iodine and Tyrosine | 90 A | $0.33 |
| 6 | Life Extension Thyroid Support Complex | 90 A | $0.90 |
| 7 | Natural Factors Liquid Kelp | 90 A | $0.01 |
| 8 | Thorne Advanced Nutrients | 88 A | $2.40 |
| 9 | Thorne Basic Nutrients 2/Day | 88 A | $0.60 |
| 10 | Thorne Basic Prenatal | 88 A | $1.23 |
| 11 | Thorne Men's Multi 50+ | 88 A | $1.87 |
| 12 | Thorne Emotion Balance Support | 87 A | $1.05 |
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 Iodine should I take?
The typical range is 150-300mcg daily. Long-term at RDA
When should I take Iodine?
Any time. Optional.
Which form of Iodine is best?
Potassium iodide — Precise dosing. Other forms in the catalog: Kelp, Nascent iodine.
Is Iodine safe?
Commonly reported: Usually well tolerated. Serious warnings: Excess can affect thyroid. Safe
Which Iodine supplement scores highest?
Pure Encapsulations Iodine (potassium iodide), at 92/100. 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 mcgIodine has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
Iodine dosage reference →Primary uses
- Thyroid hormone synthesis
- Iodine deficiency
- Goiter prevention
- Thyroid hormone production
- Metabolism
- Brain development
- Energy
What systematic reviews concluded
Outcomes that systematic reviews of Iodine reached a verdict on: 1 unclear. Each is quoted from a review and linked to it on PubMed. How these were read.
Not enough to say: ear discharge resolution (topical iodine for csom).
1 finding from reviews in specific patient groups (such as cancer, pregnancy or surgery) is not shown here.
How it works
- Component of T3 and T4 thyroid hormones
- Required for thyroid function
- Supports metabolic rate
Dosage
- Typical range
- 150-300mcg daily
- Timing
- Any time
- With food
- Optional
- Duration
- Long-term at RDA
- Special populations
- Pregnancy requires more
Forms
- Potassium iodide
- Kelp
- Nascent iodine
Safety
Common side effects
- Usually well tolerated
Contraindications
- Thyroid disorders without guidance
Products containing Iodine
Top-scoring supplements in our catalog that list Iodine 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
Essential for thyroid function
Grade A: Multiple well-designed human trials support the main claims.
Related in Mineral
Check a full stack
Formulate's free interaction checker lets you paste in any combination of supplements and medications at once — every pairing flags severity, timing, and cited evidence.
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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.