If there is a "nuclear event" and you are down-wind, you need to take KIO3 (potassium iodate) anti-radiation tablets before the radioactive plume reaches you.
If you do not have KIO3 at the time of the event, then it is most likely too late to take a thyroid blocker unless the authorities can reach you with the proper dose during fallout conditions.
KIO3 is a thyroid blocker and is used world-wide to help prevent radioactive damage to the thyroid in the event of nuclear incidents.
If a nuclear bomb detonates or a nuclear power plant is compromised or has a melt-down, then radioactive iodine is usually released into the air and surrounding environment.
Radioactive Iodine (I-131) can destroy the thyroid of humans and animals. Even small amounts of I-131 can cause cancer of the thyroid. By taking KIO3, or anti-radiation tablets, the thyroid becomes saturated with "good iodine" and cannot absorb the "bad iodine" I-131.
Animals or pets can take KIO3 too.
Take these 170mg tables only as directed by authorities or if radioactive fallout is imminent. Keep out of reach of children. Each bottle has 60 tablets.
Use K103 when directed by authorities or exposure to radioactive fallout is imminent. Examples: downwind from nuclear explosion or reactor leak. Discontinue when authorities announce "all clear" (3 to 15 days).
Adults 12 years and older - 1 tablet daily for 3 to 14 days. If need be... children 3 to 12 years, 1/2 tablet for 3 to 14 days. Children month to 3 years, 1/4 tablet for 1 to 3 days. Newborn to 1 month, 1/8 to 1/4 tablet for 1 to 3 days.
Tablets may be crushed and mixed with juice or milk.
WARNING: See your physician before taking KIO3 if you have iodine allegies, dermatitis, vasculitis, thyroid disease or kidney problems.