Does potassium iodide protect against nuclear radiation?


With the partial meltdown of the Fukushima Daiichi nuclear power plant, there has been a run on potassium iodide (KI). The over-the-counter medicine is out of stock at many pharmacies. Even though experts do not believe the radiation will make it all the way to our west coast, many Americans are still worry about possible radiation poisoning. We live only about 50 miles from the Pacific Ocean so I’m a little worry too. Should I stock up on potassium iodide tablets to protect my family against nuclear radiation? No idea. Until this week, I have not even heard of potassium iodide. That’s why I decided to do a little research and write about it on my dad blog.

What is potassium iodide?
Potassium iodide is a salt of stable iodine, which is an important chemical needed by the body to make thyroid hormones. Our bodies normally absorb stable iodine from the food we eat. However, we can also ingest stable iodine in medicine form (KI). When taken in the recommended dose, KI is effective in reducing the risk of thyroid cancer from radiation poisoning.

How does it work?
When you ingest KI, it floods the thyroid with stable iodine. This prevents the gland from absorbing the radioactive iodine released by a breached nuclear plant. KI does not prevent radioactive iodine from entering the body, but it is very effective in blocking radioactive iodine from being absorbed into the thyroid gland. In the absence of KI, the thyroid gland would quickly absorb radioactive iodine. Keep in mind that KI does not protect other body parts and it does not protect against other radioactive elements (other than radioactive iodine). In addition, KI cannot reverse the damage already caused by radioactive iodine.

What are the side effects?
Side effects include intestinal upset, allergic reactions (possibly severe), rashes, and inflammation of the salivary glands. Newborns less than one month old can develop hypothyroidism (thyroid hormone levels that are too low) if they receive more than one dose of KI. Hypothyroidism can cause brain damage. Infants who receive KI should have their thyroid hormone levels checked and monitored by a doctor.

What’s the dosage?
KI is available in tablet (130 mg and 65 mg) and liquid forms. Each milliliter (mL) of the liquid solution contains 65 mg of KI. In the event of a nuclear radiation emergency, here are the FDA’s suggested doses:

  • Adults should take a 130 mg tablet (two mL of liquid)
  • Women who are breast feeding should take the adult dose of 130 mg (two mL of liquid)
  • Children between 3 and 18 years of age should take 65 mg (one mL of liquid)
  • Children who are 150 pounds or more should take the full 130 mg adult dose (two mL of liquid)
  • Infants and children between 1 month and 3 years of age should take 32 mg (½ mL of liquid)
  • Newborns from birth to 1 month of age should be given 16 mg (¼ mL of liquid)

Who shouldn’t take it?
People who shouldn’t take KI include individuals with iodine sensitivity and people with dermatitis herpetiformis and hypocomplementemic vasculitis. People with multinodular goiter, Graves’ disease, and autoimmune thyroiditis should use KI under the supervision of a doctor.

Should you stock up on potassium iodide?
As I mentioned previously, the experts think it’s very unlikely that the nuclear radiation will reach our west coast. Then again, many experts thought there were enough safe guards in place to prevent a meltdown of the Japanese nuclear power plant. Turns out the experts didn’t factor in Mother Nature. In addition, the U.S. Surgeon General stated that stocking up on potassium iodide is a good precautionary move because you can’t be over-prepared. I have not made up my mind yet. I don’t want to over-react and contribute to the run on iodine tablets. On the other hand, it will be harder to find the longer I wait. Currently, potassium iodide is still available from Amazon.

Warning: I’m not a doctor. Even though KI is an over-the-counter medication, you should consult a doctor before taking it.

Sources: Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC)


5 thoughts on “Does potassium iodide protect against nuclear radiation?

  1. Are you aware that they are expecting some of the radiation to hit the Californa area tommorrow? (this is from the UN). They don’t know the amounts yet, but as much as the Japanese goverment is covering up what is happening, I am a little concerned. Not so much about exposure as much as it getting into our food chain.

    1. I didn’t hear about the radiation coming to California. The officials here in Oregon don’t expect anything to show up here, but you never know. I’m worry about food contamination too, especially since some of the food our family eats come from Asia.

  2. Thanks for the extra information. I’m in OR as well and am trying not to let what’s happening there overwhelm me too much with how it will affect us here. I can’t help but wonder if the downplaying of the situation is just simply meant to defuse panic. I think, ultimately, it’s just good to be prepared.

    My heart goes out to the Japanese people…

    1. We think alike. I was wondering the same thing when I saw yesterday’s press conference. They sure had a lot of people telling us not to worry. That makes me worry. Hopefully the Japaneses get the reactors contain soon. If not for, then for the people that live near there.

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