Potassium Iodide (KI) is not an ‘Anti-Radiation’ Drug

KI Will Not Protect You from the Health Effects of a Nuclear Bomb Explosion

Radiation from radioactive fallout is the biggest threat to your health after a nuclear detonation (explosion). Fallout is made up of hundreds of types of radioactive materials.
KI protects only your thyroid after breathing, eating, or drinking something that is contaminated with high amounts of one type of radioactive material: radioactive iodine (I-131).
There is a relatively small amount of radioactive iodine in fallout compared to other types of radioactive materials that can cause harm just by external exposure. KI would not protect you against the harmful health effects of any radioactive materials other than radioactive iodine.
If you were in a situation to take in enough radioactive iodine for KI to be helpful, you would have been exposed to deadly levels of external radiation from fallout.

The best protection in a nuclear detonation is to avoid radiation exposure from fallout by getting inside, staying inside, and staying tuned for instructions from local officials.

The risks of focusing on KI following a nuclear detonation include
- You may think you are protected against radiation exposure when you are not.
- Leaving your shelter or home to seek KI could expose you to dangerous levels of radiation and put you and your loved ones at greater risk.

Unlike a nuclear detonation, a nuclear power plant emergency could release radioactive iodine in quantities high enough to where KI would be helpful. If public health officials determine that you should take KI, they will provide instructions on where to get KI and how to use it.
- KI can cause harmful health effects when not taken exactly as directed by a healthcare provider or public health official. Taking more KI than recommended can cause severe illness or death.
- Some people have harmful health effects, like gastrointestinal upset, rashes, or allergic reactions from KI even when taken correctly.