Potassium Iodide for Radiation Exposure

potassium iodide for radiation
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In the event of a radiation emergency, potassium iodide is often used to protect the thyroid gland. A salt compound sold in tablet form, potassium iodide helps stop the thyroid from absorbing radioactive iodine (a potentially dangerous substance released into the air following a nuclear accident). But while potassium iodide may help block radioactive iodine in people directly exposed to radiation, taking potassium iodide in advance of exposure is considered ineffective and may actually harm your health.

Why Do People Take Potassium Iodide?

Also known as iodine-131, radioactive iodine is found in large amounts in the steam released during nuclear accidents. When radioactive iodine is inhaled or taken into the body through contaminated food or drink, it can accumulate in the thyroid and release DNA-damaging radiation. When left untreated, this buildup of radioactive iodine can lead to thyroid cancer. By preventing the thyroid's absorption of radioactive iodine, potassium iodide may shield the thyroid from harm and reduce thyroid cancer risk.

Health Risks

When taken as recommended by public health or emergency management officials, the benefits of potassium iodide outweigh the risks. However, the Centers for Disease Control and Prevention (CDC) warn that improper use of potassium iodide can cause severe illness or even death.

Adverse effects of potassium iodide range from upset stomach, headache, and rashes to severe allergic reactions, irregular heartbeat, and inflammation of the salivary glands. What's more, potassium iodide may be harmful to people with thyroid disease and certain skin disorders (such as dermatitis herpetiformis or urticaria vasculitis), as well as individuals who are allergic to iodine.


According to the CDC, potassium iodide should only be taken on the advice of emergency management officials, public health officials, or your doctor. Available without a prescription, potassium iodide is available in over-the-counter medications approved by the U.S. Food and Drug Administration and in dietary supplements.

It's important to note that potassium iodide may not provide complete protection against the thyroid-harming effects of radioactive iodine. Potassium iodide's effectiveness depends on several factors, including the amount of radioactive iodine to which you're exposed and the length of time that passes between radiation exposure and the consumption of potassium iodide.

If you're concerned about possible exposure to radiation, it's crucial to talk to your doctor before pursuing treatment with potassium iodide.

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