KI Pills: Your Complete Guide to Potassium Iodide
We researched 60+ potassium iodide products so you don't have to. Only four carry FDA drug approval for radiation emergencies — and most people buy the wrong one.
Our Top 3 Picks for 2026
iOSAT 130mg
- Strength:
- 130mg
- Count:
- 14 tablets
- Shelf:
- 10 years
ThyroSafe 65mg
- Strength:
- 65mg
- Count:
- 20 tablets
- Shelf:
- 6-7 years
ThyroShield Supplement 120ct
- Strength:
- 130mg
- Count:
- 120 tablets
- Shelf:
- Check label
The 30-Second Version
There are 60+ KI products on Amazon. Only four have FDA drug approval.
For adults: iOSAT 130mg. One pill, full dose, 10-year shelf life.
For families with kids: ThyroSafe 65mg. No splitting for ages 3-12.
On a budget: ThyroShield supplement, $0.12/tablet — but it's not FDA-approved.
KI only protects your thyroid. It only works against radioactive iodine. It's not an anti-radiation pill.
Only take it when officials say to. Never preventatively.
Quick Dose Table
FDA-recommended potassium iodide dosing by age and weight. Don't guess.
| Age / Weight | KI Dose | 130mg Tablets | 65mg Tablets |
|---|---|---|---|
| Adults 18+ | 130 mg | 1 tablet | 2 tablets |
| Adolescents 12-18 (≥150 lbs) | 130 mg | 1 tablet | 2 tablets |
| Adolescents 12-18 (<150 lbs) | 65 mg | ½ tablet | 1 tablet |
| Children 3-12 | 65 mg | ½ tablet | 1 tablet |
| Children 1 month-3 years | 32 mg | ¼ tablet | ½ tablet |
| Infants <1 month | 16 mg | ⅛ tablet | ¼ tablet |
Source: FDA Potassium Iodide Guidance. Pregnant/nursing women take adult dose. Use our dose calculator for exact amounts.
Going Deeper
How KI Actually Works
The science in plain English — what KI protects and what it doesn't.
iOSAT vs ThyroSafe
Head-to-head comparison of the two FDA-approved KI tablets.
KI Dosing by Age
Complete guide with tablet-splitting math and mixing methods.
FDA vs Supplement KI
Is FDA approval worth the extra cost? We break it down.