People have been drinking caffeinated beverages for centuries, and popping caffeine pills for decades, and the Food and Drug Administration currently puts no hard limit on caffeine content in food. But the recent death of an Ohio teen who ingested the pure powdered form of caffeine has the FDA warning consumers against the incredibly potent stimulant.

The amount of caffeine in a cup of coffee is often high, but generally considered safe. However, the FDA says that a single teaspoon — tea, with a lower-case “t” — is the equivalent of 25 cups of coffee.

Even if you think you could handle that jolt to your system, the FDA warns that “It is nearly impossible to accurately measure powdered pure caffeine with common kitchen measuring tools and you can easily consume a lethal amount.”

According to the warning, symptoms of caffeine overdose can include rapid or dangerously erratic heartbeat, seizures and death. Symptoms of caffeine toxicity include vomiting, diarrhea, stupor and disorientation.

“These symptoms are likely to be much more severe than those resulting from drinking too much coffee, tea or other caffeinated beverages,” writes the FDA, which is advising people to just say no to powdered caffeine.

Caffeine has come under fire in recent years, especially with regard to its use in so-called energy drinks. Of even greater concern are people who mix highly caffeinated beverages with alcohol, as the stimulating effects of caffeine may mask the drinker’s level of intoxication or allow the drinker to think they are less drunk than they really are.

Caffeine is also being added to non-beverage items, like the Wrigley’s Alert Energy gum, that the company pulled the plug on in 2013 after the FDA announced it was investigating food products with added caffeine.

The Center for Science in the Public Interest, which has ben pushing the FDA to do more about alerting consumers to the possible hazards of consuming too much caffein, says the agency’s warning about pure caffeine is a “step forward” but that the FDA should “take whichever additional measures it can against these products.”

This includes using its authority to put limits on caffeine content, and requiring warning labels when necessary.

“The overuse and misuse of caffeine in the food supply is creating a wild-west marketplace,” CSPI explains, “and it’s about time the sheriff noticed and did something.”

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.