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Potassium Iodide Pills: Can They Protect You From Radiation Exposure?

Michael  W. Smith, MD - Blogs
By Michael W. Smith, MDBoard-certified internistMarch 16, 2011
From the WebMD Archives

In the wake of the nuclear plant meltdown in Japan, Americans are buying up potassium iodide pills – also called iodine pills.

Potassium iodide helps prevent some of the damaging effects of radiation.

The thyroid gland in the neck is one of the most sensitive organs in the body to radiation. Exposure to high levels of radiation — as occurs during a nuclear plant meltdown — can lead to thyroid cancer.

So how does potassium iodide help?

The thyroid uses iodine normally to make thyroid hormone. The radiation from a nuclear event releases radioactive iodine into the air. When the radioactive iodine enters the body, the thyroid quickly scoops it up.

Taking potassium iodide pills temporarily stops the thyroid. If taken prior to radiation exposure, the iodine pills counter the effect of the radioactive iodine on the thyroid. This helps prevent the development of thyroid cancer down the road.

Usually, only one dose of potassium iodide is needed since a single dose protects the thyroid gland for 24 hours — assuming you remove yourself from the exposure area.

It’s important to note that potassium iodide pills protect only the thyroid. They don’t prevent your body from taking in the radiation and don’t help prevent radiation damage to other parts of the body.

Potassium iodide is available without a prescription as pills or drops. It is also found in radiation exposure kits. But taking iodine pills is not something you want to do unless instructed by your doctor or emergency management officials.

There are also other medicines that help if exposed to various radioactive substances. They treat contamination from various radioactive substances, including plutonium, by increasing elimination from the body.

It’s important to remember that experts are not suggesting anyone in the U.S. take potassium iodide, and of course there is no current risk of radiation exposure from a nuclear meltdown in the U.S.

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About the Author
Michael W. Smith, MD

Michael Smith, MD, CPT, is a board-certified internal medicine doctor and WebMD’s Chief Medical Editor. He is also an American Council on Exercise certified personal trainer with a passion for helping people live a healthy, active lifestyle. He appears regularly as an expert on national and local broadcast media.

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