What Does Potassium Iodide Do? Demand for Drug Spikes Amid Fears of Nuclear War

As Russia's invasion of Ukraine continues, the placement of its nuclear arsenal on alert and the attacks on Ukraine's nuclear facilities is driving the demand for potassium iodide pills.

The reason for this is the fact that potassium iodide can offer limited protection for radioactive material released during such a nuclear incident. Yet, despite this, Specialists in Radiation Protection, HPS, warn that potassium iodide is not a "magic bullet" for radiation protection.

They explain that, if taken correctly, potassium iodide, or KI, only offers the thyroid gland protection against internal radiation from radioactive iodine (radioiodine) taken into the body. HPS writes: "It will NOT protect against external radiation or internal radiation from radionuclides other than radioiodine.

"This salt, if taken either before or very soon after a radioiodine intake and if taken in the proper dose, will block the uptake of radioiodine by the thyroid."

The Centers for Disease Control and Prevention (CDC) explains that in the event of a nuclear incident like the explosion of a nuclear reactor or the detonation of a nuclear weapon, radioactive iodine is released into the air.

In the majority of cases, when this radioactive iodine enters the body, usually by being breathed in, it is quickly absorbed by the thyroid gland. Once in the thyroid radioiodine can destroy the gland or cause cancers.

Following the explosion of Chernobyl in Ukraine in 1989, the uptake of radioactive isotopes of iodine, particularly iodine-131, caused a wave of thyroid cancers, especially amongst children still observed 14 years after the accident.

The CDC states that potassium iodide can block the thyroid gland from taking up radioiodine. This is because the thyroid doesn't distinguish between stable and radioactive iodine and will absorb both from the bloodstream.

That means when a person takes potassium iodide in the usually recommended dose of 130 milligrams for adults, the thyroid becomes saturated with stable iodine, becoming "full" and meaning the gland can't absorb radioiodine. This usually leads to radioiodine being excreted from the body in urine. One dose of potassium iodide usually protects a person for 24 hours.

The CDC adds that potassium iodide can't protect a person's other organs from damage caused by radioactive iodine. Nor can potassium iodide protect any part of the body, including the thyroid, from any radioactive material other than iodine released by a nuclear event.

In addition to this, how effective potassium iodide is at protecting the thyroid is dependent on several factors. The CDC lists some of these as how much time passes between contamination with radioactive iodine and taking potassium iodide, adding that the sooner this happens the better.

How quickly the potassium iodide is absorbed into the blood, and how much radioiodine a person is exposed to, also play a role in the effectiveness of potassium iodide.

The CDC warns that people should not take potassium iodide if they are allergic to iodine, or if they have certain skin disorders like dermatitis herpetiformis or urticaria vasculitis.

Children are particularly vulnerable to radioiodine absorption by the thyroid gland, meaning that alongside pregnant women, they should be prioritized in the distribution of potassium iodide pills.

Potassium iodide
A bottle of Potassium Iodide is seen at the West Marin Pharmacy on March 15, 2011. Fears regard a possible nuclear event are driving sales of Potassium Iodide which can offer limited protection from radioactive iodine. Justin Sullivan/GETTY