Lugol's Solution is used for a wide variety of applications.
When used on humans, it's applications include being used as an antiseptic, topical disinfectant, and promoting a healthy thyroid.
It is also used as an emergency water disinfectant.
Lugol's Solution can also be taken to cure iodine deficiency and to keep the thyroid from absorbing iodine-131, a highly radioactive isotope of iodine common in nuclear fallout.