Too much of a good thing can be bad. Sometimes it only takes a spoonful.

Yesterday the Food and Drug Administration released a warning about powdered pure caffeine. Usually added to drinks before workouts for an energy boost or to aid weight loss, the white substance is readily available online.

The federal advisory comes weeks after an autopsy ruled the death of a teen in LaGrange, Ohio, a caffeine overdose.

High school student and wrestler Logan Stiner died in May, days away from graduation, after consuming one teaspoon of powdered caffeine—the equivalent of drinking 25 cups of coffee or 70 cans of Red Bull. The 18-year-old suffered seizures. The county coroner found more than 70 micrograms of caffeine per milliliter of blood in his system—more than 20 times that of an average coffee drinker.

“The difference between a safe amount and a lethal dose of caffeine in these powdered products is very small,” FDA spokesperson Jennifer Dooren told the Associated Press.

Similarly, caffeine tablets have been popular as study aids among college students. Though they contain much lower dosages of the stimulant (roughly the amount of one to three cups of coffee), the agency has received a report of a 19-year-old who died from taking too many and warns against the pills as well.

Federal authorities don’t regulate those substances because they’re sold as dietary supplements. As is the case with energy drinks, Four Loko, and caffeine inhalers, powdered caffeine especially attracts young people. In its statement about the product, the FDA advises parents to take heed.

“I can’t believe you can buy this,” Henry Spiller, a physician who heads a poison control center at the Nationwide Children’s Hospital in Columbus, Ohio, told the AP. “Honestly, I mean, it’s frightening. It makes no sense to me.” The center received three reports of hospitalization from caffeine powder use over the course of one week this month.

The FDA, which took caffeinated alcohol off shelves in 2010, is examining powdered caffeine and will consider taking regulatory action.