[11] Preoperative administration of Lugol's solution decreases intraoperative blood loss during thyroidectomy in patients with Graves' disease.

The idea stemmed from the fact that, in the laboratory, Lugol's iodine appeared to kill sperm cells even in such great dilutions as 1:32.

[19] Because it contains free iodine, Lugol's solution at 2% or 5% concentration without dilution is irritating and destructive to mucosa, such as the lining of the esophagus and stomach.

[22] The Global Harmonized System of Classification and Labeling of Chemicals categorizes this as Category 2 with a hazard statement "Fatal if swallowed".

However it is not used to treat certain autoimmune causes of thyroid disease as iodine-induced blockade of iodine organification may result in hypothyroidism.

[25] Other sources state that pure potassium iodide solution in water (SSKI) was eventually used for most of the thyroid protection after this accident.

Potassium iodide does not provide immediate protection but can be a component of a general strategy in a radiation emergency.

[27][failed verification] Historically, Lugol's iodine solution has been widely available and used for a number of health problems with some precautions.

[citation needed] Until 2007, in the United States, Lugol's solution was unregulated and available over the counter as a general reagent, an antiseptic, a preservative,[31] or as a medicament for human or veterinary application.

Potassium iodide renders the elementary iodine soluble in water through the formation of the triiodide (I−3) ion.