Feel Free customers say the kratom drink is making them sick. Toothless FDA rules on dietary supplements are helping it remain a bestseller

For two decades, 5-hour Energy, an energy drink sold in colorful two-ounce bottles in convenience store chains nationwide, has been the go-to booster for thousands of tired truckers and cramming college students. But last year, for the first time, it was reportedly surpassed as one major national convenience store chain’s top energy drink—by a product that had been on that chain’s shelves for only four months.

This up-and-coming brand, Feel Free, was marketing itself as something slightly different.