The FDA says people should stop using Hydroxycut products because they've been linked to a series of serious liver injuries.
Sales topping about nine million last year alone, confirm the widespread use of Hydroxycut dietary supplements.
But in strong language that impresses even academics, the FDA is now telling consumers to stay away from them.
"I think the FDA's taking the appropriate steps, using strong language to make sure that consumers know not to use these products because we're concerned with these report of liver injury and even one death with the use of Hydroxycut products," said Macary Marciniak, of the University of North Carolina School of Pharmacy.
One case of death from liver failure another where a user needed a liver transplant is what researchers have to back them up
Iovate Health Sciences of Canada markets Hydroxycut products as fat burners, energy-enhancers and low carb diet aids.
The FDA says Hydroxycut products contain a variety of ingredients and herbal extracts and can't say yet exactly which one is causing the problem."
It might actually be a blend of those ingredients.
"It is possible it is from one active ingredient in that product. It is also possible that it's a combination, a combination of medications that are available in that product," said Marciniak.
But for now, even the manufacturer wants Hydroxycut off the shelves until science can figure what's wrong with it.