FTC Consumer Alert

Potassium Iodide: What You Need to Know

Produced in cooperation with the Centers for Disease Control and Prevention and the Food and Drug Administration.

Recent reports of events in Japan are raising concerns in the U.S. that radioactive iodine may find its way across the Pacific Ocean. This concern has led to a run on potassium iodide (KI) pills and drops, which can help prevent thyroid cancer – one of the biggest risks from contamination with radioactive iodine.

However, public health experts agree that people in the U.S. should not buy or take potassium iodide unless specifically notified or instructed by public health officials.

Still, scam artists are doing their best to persuade you to think otherwise. The Federal Trade Commission (FTC), the nation's consumer protection agency, cautions that fraudsters follow the headlines, tailoring their offers to prey on current consumer fears and vulnerabilities.

Forewarned is Forearmed

If you're thinking about buying potassium iodide, the FTC, the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA), urge you to:

  • Talk to your healthcare professional before you buy. Some people are allergic to iodine and shouldn't take potassium iodide. (A seafood or shellfish allergy doesn't necessarily mean that you are allergic to iodine.) If you are unsure about this, consult your doctor. People with certain skin conditions (for example, dermatitis herpetiformis or hypocomplementemic vasculitis), as well as people with nodular thyroid with heart disease, should not take KI.
  • Understand that taking potassium iodide cannot:
    • prevent radioactive iodine from entering your body. It can protect the thyroid from radioactive iodine, but not other parts of your body.
    • reverse the health effects caused by radioactive iodine once damage to the thyroid has occurred.
    • protect your body from radioactive elements other than radioactive iodine. That is, if radioactive iodine is not present, taking potassium iodide will not help you
  • If you decide to buy KI, buy only from a reputable source. Iosat, ThyroSafe, and ThyroShield are the only FDA-approved KI products, and are the only KI products that may be legally marketed and sold in the U.S. For more information on these
    products, contact:
  • Follow dosing instructions carefully. More is not better: Taking a higher dose of KI – or taking it more often than recommended – doesn't offer any additional protection; in fact, it can cause severe illness – even death.

For More Information

Centers for Disease Control

Food and Drug Administration

U.S. Department of Agriculture, Food Safety and Inspection Service (USDA, FSIS)

The FTC works to prevent fraudulent, deceptive and unfair business practices in the marketplace and to provide information to help consumers spot, stop and avoid them. To file a complaint or get free information on consumer issues, visit ftc.gov or call toll-free, 1-877-FTC-HELP (1-877-382-4357); TTY: 1-866-653-4261. Watch a video, How to File a Complaint, at ftc.gov/video to learn more. The FTC enters consumer complaints into the Consumer Sentinel Network, a secure online database and investigative tool used by hundreds of civil and criminal law enforcement agencies in the U.S. and abroad.

March 2011

Last Modified: Monday, March 21, 2011