The Food and Drug Administration is warning against 28 weight-loss products you might be tempted to try after the holidays.
The FDA says they contain unlisted ingredients, including powerful appetite-suppressing drugs and a suspected carcinogen.
A spokeswoman says in some cases, they have prescription drugs in amounts that greatly exceed their maximum recommended dosages.
The FDA says none of the supplements lists the dangerous ingredients on the label.
The pills are advertised as "natural" fat busters. Some suggest they are innovative "herbal" remedies from Asia.
The FDA is considering criminal charges against some of the companies because they have not responded to requests for recalls.