The tablets help mitigate the threat of long-term thyroid cancer, the likes of which were seen after the Chernobyl meltdown, particularly in high-risk groups like infants and children.

In Belgium, nearly 30,000 residents went to pharmacies for free pills following Russian President Vladimir Putin’s announcement to put its nuclear deterrent forces on high alert and recent fighting at nuclear power plants in Ukraine, according to the Brussels Times.

Meanwhile, Bloomberg reported that there has been a 100-fold increase in demand for tablets in Finland ever since Russia invaded Ukraine, with pharmacies out of stock across the country. 

What in theory may sound sensible to have on hand can prove hazardous in real life if instructions aren’t followed carefully. Depending on one’s age, they may not even bring a net benefit.

“Taking [potassium iodide] more often than recommended does not offer more protection and can cause severe illness or death,” the U.S. Centers for Disease Control warns. 

The tablets work by saturating the thyroid with iodine for 24 hours, blocking the intake of highly radioactive iodine-131 that would otherwise be readily absorbed by the organ through contaminated air, food, or water. 

In the event of a nuclear accident or attack, the tablet’s 24-hour effect provides valuable time to seek shelter from this unstable iodine isotope. Itself a by-product of nuclear fission, iodine-131 begins to decay after just eight days.

No help against other radioactive isotopes

Furthermore, these tablets should not be taken unless there is actually a risk of imminent exposure. Ingesting the medicine preventatively without supervision can end up doing more harm than good. 

With many adults suffering from some form of overactive thyroid, ingesting high-dosage potassium iodide can cause harmful side effects including acute cardiovascular failure, which outweigh the increased risk of developing cancer.

Consequently, the Centers for Disease Control only recommends individuals 40 years and younger need take them in the event of a fallout.

Moreover, iodine is not a silver bullet solution for protecting oneself in a fallout. It cannot help against the threat of other common radioactive elements emitted in a blast, such as cesium-137 or strontium-90.

As a result, the chair of the Drug Commission of German Pharmacists strongly advised last week against self-administering such tablets. 

“Not only does this pose considerable health risks, it currently offers no advantage,” said Martin Schulz, citing the lack of any suspicious radioactivity emanating from Ukraine.

The commission added there was “no rational argument at present for taking high dosage iodine tablets due to the situation in Ukraine,” adding authorities had stockpiled reserves of nearly 190 million tablets should the need ever arise.