As Japan struggles to stabilize the nuclear reactors damaged by last week’s earthquake, the Mission, like the rest of the country, is in the middle of a good old-fashioned run on potassium iodide.

It’s sold out at the Rainbow Grocery Cooperative. It’s sold out at Valencia Whole Foods. The waiting list for the next shipment at the Scarlet Sage Herb Company is at 25 and climbing.

“We sold out of it over the weekend,” says Dino Lucas, owner and herbalist at Scarlet Sage. “Someone just walked in and bought our entire stock.”

Potassium iodide is a salt that lessens the amount of radiation the human thyroid can absorb by ensuring that the thyroid is already full of non-radioactive iodine. According to the LA Times, the comparatively low levels of thyroid cancer in the Polish cities unfortunate enough to be downwind from Chernobyl are due to the distribution of iodide tablets. According to the BBC, the U.S. government recommends that states have enough potassium iodide on hand for every person living within 10 miles of a nuclear power plant. (That’s not us. California only has two: Diablo Canyon in San Luis Obispo county and San Onofre in northern San Diego county).

Potassium iodide is not exactly a big seller normally, says Lucas. The store’s entire stock was about four bottles. It’s primarily taken for hypothyroidism. Lucas suspects that the demand has been driven by the seemingly infinite loop of cable news stories about the shortage.

When was the last time the store had a run like this? “Every time Doctor Oz recommends something.”

“Oh! Dr. Oz!” groans another employee, with world-weary familiarity.

Once upon a time in America, people concerned with their health actually took radioactive health tonics. This came to an end roughly around the time that a very wealthy Pittsburgh industrialist died from drinking cases and cases of it.

Potassium Iodide is arguably better for you than radioactive tonic, but not by much. “My fear is that people are going to take too much of it,” says Lucas. About 8 percent of the population is likely to develop a thyroid problem from taking it. One percent of those who take it, on average, will break out in a rash. Some people are allergic to iodine — usually the same people who are allergic to shellfish. The symptoms are the same: swollen lips, tongue, mouth, and constricted airways.

Also: It tastes bad.

Japan is the place that needs potassium iodide: 12 hours before exposure to radiation, and a few drops or tablets a day for the next few days. In their case, the risk of cancer is worse than the risk of possibly throwing your thyroid out of whack.

For those worried about radiation exposure in minimal quantities, there are less risky ways to up your iodine intake, or otherwise detoxify. Chef and nutritional consultant Nicole LoBue, who teaches classes on food as medicine at the Studio for Urban Projects, recommends miso soup with a shiitake dashi broth, and kombu seaweed. Also good: kelp, ginseng, red algae, chlorella (which is a kind of green algae), anything with vitamin C, brazil nuts (for the selenium), coconut butter, olive oil, keeping away from sugar and staying hydrated.

“We’re trying to direct people to other organ systems,” says Lucas of those who come in and are distressed to find that the potassium iodide is gone. “The liver. The lungs. Blood isn’t exactly an organ, but blood cleansing.” She recommends mushrooms like shiitake, maitake and reishi, as well as milk thistle, red clover and burdock. “You can just make a soup with miso, burdock, daikon, seaweed…” she trails off. “I’m still wondering about kombucha. Supposedly they drank that after Chernobyl.” Eating whole foods is a good idea, she says, because it’s hard to consume too many of them, the way that people can get carried away and, say, take too many seaweed supplements.

The last time Lucas remembers people coming to the store en masse like this was when George W. Bush was elected the second time. It wasn’t so much that they directly asked for antidepressants, she recalls. “It’s good to get out and talk, to see what you can do.”

She’s been recommending a lot of the same things this time around. “Skullcap. Wild oats. Passionflower. Kava might be too calming.”

“There’s always chamomile,” she says. “Very simple. But very effective.”