Examples of such preparations include:[11] The antimicrobial action of iodine is quick and works at low concentrations, and thus it is used in operating theatres.

Iodine probably attacks surface proteins of enveloped viruses, and it may also destabilise membrane fatty acids by reacting with unsaturated carbon bonds.

At low doses, it is one of the options for making iodized salt, along with the more stable potassium iodate.

[17][18] Iodine-131 (usually as iodide) is a component of nuclear fallout, and is particularly dangerous owing to the thyroid gland's propensity to concentrate ingested iodine and retain it for periods longer than this isotope's radiological half-life of eight days.

For this reason, people at risk of exposure to environmental radioactive iodine (iodine-131) in fallout may be instructed to take non-radioactive potassium iodide tablets.

[19] Before the advent of organic chelating agents, salts of iodide were given orally in the treatment of lead or mercury poisoning, such as heavily popularized by Louis Melsens and many nineteenth and early twentieth century doctors.

As an iodine supplement, it is given by mouth once per year to prevent endemic goitre in remote communities.