IodineDoes potassium iodide protect against radiation?
Updated 10 Nov 2026
Short answer
It protects the thyroid from radioactive iodine. The US FDA approved potassium iodide to block the thyroid and lower the risk of thyroid cancer in radiation emergencies that release radioactive iodine.[1] FDA advises 16 to 130 mg a day, by age, until the risk of exposure ends.[1]
After the Chernobyl accident in 1986, Poland gave potassium iodide widely, and thyroid cancer in children did not rise much. In Belarus and Ukraine, where it was not used, thyroid cancer in children and teenagers rose sharply.[1] People with iodine deficiency take up more radioactive iodine and have a higher risk.[1]
Sources (1)
- Iodine: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
More about iodine
What is iodine?Which foods contain iodine?What is iodine used for?What happens if you do not get enough iodine?Is iodine safe?Do you need an iodine supplement in pregnancy?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.