FTC Consumer Alert

Federal Trade Commission Bureau of Consumer Protection Division of Consumer & Business Education

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.
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March 2011

➤ 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:

•	 Anbex, Inc. for Iosat Tablets (130 mg) at 212-580-2810 (M-F 9am-5pm EST), at 

1-866-463-6754 (other times), or www.anbex.com

•	 ThyroSafe Tablets (65 mg) at 1-866-849-7672 or www.thyrosafe.com/recip.html

•	 Fleming & Company, Pharmaceuticals for ThyroShield Solution at 636-343-8200 or 

www.flemingcompany.com or www.thyroshield.com

➤ 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 

•	 Radiation Emergencies at www.bt.cdc.gov/radiation

•	 Potassium Iodide at http://emergency.cdc.gov/radiation/ki.asp

•	 Frequently Asked Questions About a Radiation Emergency at 

http://emergency.cdc.gov/radiation/emergencyfaq.asp

Food and Drug Administration

•	 Frequently Asked Questions on Potassium Iodide at www.fda.gov/Drugs/

EmergencyPreparedness/BioterrorismandDrugPreparedness/ucm072265.htm

•	 Radiation Emergencies at www.fda.gov/Drugs/EmergencyPreparedness/

BioterrorismandDrugPreparedness/ucm063807.htm

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

•	 For a table of links to each State’s Department of Health page, visit

www.fsis.usda.gov/Fsis_recalls/State_Departments_of_Public_Health/index.asp

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.