The Complete Guide to Potassium Iodide Pills
Compare FDA-approved and supplement KI products, calculate your family's exact dose, and make an informed decision — backed by CDC, FDA, and WHO guidance.
The Potassium Iodide Problem
There are over 60 potassium iodide products on Amazon alone. Only 4 have FDA approval for radiation emergencies. Most buyers can't tell the difference — and in an emergency, that difference matters.
FDA-Verified Reviews
We verify every product's regulatory status through the FDA's DailyMed database — so you don't have to guess which KI is real.
Family-First Dosing
Our dosage calculator gives you exact tablet counts for every family member, from infants to adults, based on FDA/CDC guidelines.
No Conflicts of Interest
We earn affiliate commissions, but rankings are based on FDA status, shelf life, and value — not who pays us more. See our disclosure.
The Two FDA-Approved Leaders
If you want government-verified protection, your choice comes down to two products. Here's how they compare.
iOSAT 130mg
- Strength130mg per tablet
- Shelf Life10 years
- FDA Since1982
- Best ForAdults, stockpiling
ThyroSafe 65mg
- Strength65mg per tablet
- Shelf Life6–7 years
- FDA StatusANDA-Approved
- Best ForFamilies with children
How Potassium Iodide Protects Your Thyroid
The science is simple — and it's been proven in every major nuclear disaster since Chernobyl.
1. The Threat
In a nuclear emergency, radioactive iodine-131 enters the air. Your thyroid absorbs it from your bloodstream, causing DNA damage and dramatically increasing cancer risk — especially in children under 18.
2. The Shield
A single dose of potassium iodide floods your thyroid with stable, safe iodine. Within 30 minutes, your thyroid is completely saturated — like filling a sponge with clean water before it touches dirty water.
3. The Result
With the thyroid fully saturated, radioactive iodine simply passes through your body and is excreted. A single dose provides up to 24 hours of near-complete thyroid protection when taken before or shortly after exposure.
FDA Dosage Guidelines by Age
The dose depends on age — not weight. Here are the official FDA/CDC guidelines.
| Age Group | Dose (mg) | 130mg Tablets | 65mg Tablets | Liquid (65mg/mL) |
|---|---|---|---|---|
| Adults 18–40 | 130 mg | 1 tablet | 2 tablets | 2 mL |
| Adults over 40 | 130 mg* | 1 tablet | 2 tablets | 2 mL |
| Pregnant / Breastfeeding | 130 mg | 1 tablet | 2 tablets | 2 mL |
| Adolescents 12–18 (≥150 lbs) | 130 mg | 1 tablet | 2 tablets | 2 mL |
| Adolescents 12–18 (<150 lbs) | 65 mg | ½ tablet | 1 tablet | 1 mL |
| Children 3–12 | 65 mg | ½ tablet | 1 tablet | 1 mL |
| Children 1 month – 3 years | 32 mg | ¼ tablet | ½ tablet | 0.5 mL |
| Neonates (birth – 1 month) | 16 mg | ⅛ tablet | ¼ tablet | 0.25 mL |
*Adults over 40 should take KI only at higher projected thyroid exposure (>500 cGy). Source: FDA KI Guidance
Essential Reading
📋 Best KI Pills 2026
Our flagship buying guide comparing all 9 products — FDA-approved and supplement — with pricing, shelf life, and dosing analysis.
🔬 FDA vs Supplements
The critical difference between FDA-approved KI drugs and dietary supplements — and why it matters for your family's safety.
⚠️ Side Effects Guide
What to expect, when to seek emergency care, and critical drug interactions to know about before taking potassium iodide.