Mineral
Iodine (Potassium Iodide)
Also known as: KI, Potassium iodide
Essential for thyroid hormone synthesis. Deficiency common in many regions. Careful dosing needed.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Iodine (Potassium Iodide) 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 (Potassium Iodide) should I take?
The typical range is 150-300 mcg daily. Long-term safe at appropriate doses
When should I take Iodine (Potassium Iodide)?
Any. Optional.
Which form of Iodine (Potassium Iodide) is best?
Potassium iodide — Most common. Other forms in the catalog: Kelp, Lugol's.
Is Iodine (Potassium Iodide) safe?
Commonly reported: Metallic taste. Serious warnings: Excess worsens thyroid conditions, Can trigger hyperthyroidism. Safe
Which Iodine (Potassium Iodide) 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 (Potassium Iodide) has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
Iodine (Potassium Iodide) dosage reference →Primary uses
- Thyroid function
- Hormone production
- Metabolic support
How it works
- Incorporated into T3 and T4
- Essential for thyroid peroxidase
Dosage
- Typical range
- 150-300 mcg daily
- Timing
- Any
- With food
- Optional
- Duration
- Long-term safe at appropriate doses
- Special populations
- Pregnancy needs 220-290 mcg
Forms
- Potassium iodide
- Kelp
- Lugol's
Safety
Common side effects
- Metallic taste
Contraindications
- Autonomous thyroid nodules
Products containing Iodine (Potassium Iodide)
Top-scoring supplements in our catalog that list Iodine (Potassium Iodide) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Essential nutrient
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.
Open the checkerWhere does Iodine (Potassium Iodide) fit in your stack?
Answer two questions and get a stack graded on research — every ingredient scored on the evidence behind it, not the marketing.
Build my stack2 questions · free · no account needed to start
Also on iPhone — get the free app
Evidence-based supplement guides, no spam
We send a short digest when new guides drop — nothing else. No affiliate pushes, no sponsored content, unsubscribe anytime.
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.