What is Potassium Iodide?
Potassium iodide (KI) is a salt of stable (not radioactive) iodine that can help block radioactive iodine from being absorbed by thyroid gland, thus protecting this gland from radiation injury. It only protects the thyroid, but not other parts of body, from radioactive iodine. It does not prevent radioactive iodine from entering body.
How does it work?
The thyroid gland will absorb both stable and radioactive iodine. KI blocks radioactive iodine from entering the thyroid. When a person takes KI, stable iodine is absorbed by the thyroid. KI contains so much stable iodine, the thyroid gland becomes “full” and cannot absorb any more iodine — either stable or radioactive — for next 24 hours.