The iodine tablet rush

Taking iodine tablets as a precaution against the nuclear threat is unnecessary and dangerous.

After the bombing of the Ukrainian nuclear plant in Zaporizhia on 4 March (six of Ukraine's 15 nuclear reactors are located in this plant), thousands of Europeans have been rushing to buy medicines to counter the effects of radioactivity. In France, too, concern is growing and a significant increase in the number of requests for iodine tablets in pharmacies has been noted in recent days.


Because in the event of a nuclear incident, radioactive iodine can be released and, if inhaled or ingested, it can settle on the thyroid gland and thus increase the risk of cancer of this organ. To prevent radioactive iodine from accumulating in the thyroid, non-radioactive iodine (potassium iodide, stable iodine) is taken to saturate the thyroid and thus limit the binding of radioactive iodine.

Iodine is a trace element present in food and is essential for the functioning of the thyroid.

According to the Institute for Radiological Protection and Nuclear Safety (IRSN), to be effective, iodine tablets must be taken 2 hours before exposure to radioactivity, and at the latest within 6 to 12 hours afterwards. The French Nuclear Safety Agency (ASN) estimates that taking a single tablet, swallowed or dissolved in a drink, is enough to effectively protect an adult or teenager for one to two days.

However, stable iodine does not protect against all radioactive elements. If other radioactive elements are present, additional protective measures are necessary.

In addition, iodine tablets can, like any medicinal product, cause undesirable effects.

The Pharmacie Centrale des Armées is the historical manufacturer of iodine tablets in France. The SERB laboratory also has an MA (Marketing Authorisation) for potassium iodide tablets.

In France, the distribution of iodine tablets as a preventive measure is highly regulated and is only carried out free of charge to populations located within a radius of 20 km around facilities presenting a risk of radioactive iodine emissions (nuclear plants, research reactors and certain defense facilities). For people not concerned by this procedure, it is possible to obtain tablets from a pharmacy without a prescription, depending on available stocks and at a cost.

Taking iodine tablets after a nuclear event in another country depends on several factors such as the type of event, its extent, the place where it occurred and the atmospheric conditions that facilitate the transport of radioactivity.

Stable iodine should therefore only be taken immediately at the request of the prefect.

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