Some pure caffeine products are now unlawful, according to the Food and Drug Administration.
The agency said the ban focuses on liquids and powders containing pure or highly concentrated caffeine, which are often sold in large tubs containing thousands of servings — not everyday products like coffee and energy drinks.
One teaspoon of pure powdered caffeine is equivalent to 28 cups of regular coffee, the FDA says. A recommended safe serving size of pure caffeine products is usually 200 milligrams, or 1/16th of a teaspoon of powder and about 2½ teaspoons of liquid. Amounts that tiny can be tough to measure, and slight variations can be deadly.