A lot of vitamin supplement stores in California are reporting empty shelves in places where potassium iodide usually sits, ever since Japan's radiation leak at a nuclear facility after the big earthquake.
"We had a run on potassium iodide," said Susan Talerico of Elliott's Natural Foods. "Pretty much all of our products sold out within the first two hours Monday morning. Everything sold."
No word as to when manufacturers can catch up on demand.
Potassium iodide fills your thyroid gland, so if taken prior to minor radiation exposure, your body just flushes the toxin out.
Pharmacists, who fill prescription strength potassium iodide to certain thyroid patients, point out the pills only protect that part of your body, not all of it.
"Some people feel that if they take this, they won't be exposed, there's no exposure risk somehow, they're going to have this dome over them somehow," said pharmacist John Richards. "And that's just not the case."
The California Department of Public Health says this run on potassium iodide is unnecessary and that health problems can occur if taken when there is no radiation problem in California.
"It is not necessary for people 5,000 miles away to be concerned," said Dr. Howard Backer with the California Department of Public Health. "There is no radioactive iodine and you can actually have problems from excess iodide."
The state says San Luis Obispo and Orange counties, where California's nuclear facilities are located, have a stockpile of potassium iodide in case radiation leaks there.
Still, some Californians can't help but wonder if they should be prepared for the remote possibility Japan's radiation travels across the Pacific Ocean.
"The phone's been ringing off the hook. Everybody wants it," said Talerico. "They're like, 'Yeah we hear that, but we still want it.'"