If you find yourself making this common New Year’s resolution, know this: many so-called “miracle” weight loss supplements and foods (including teas and coffees) don’t live up to their claims. Worse, they can cause serious harm, say FDA regulators. The agency has found hundreds of products that are marketed as dietary supplements but actually contain hidden active ingredients (components that make a medicine effective against a specific illness) contained in prescription drugs, unsafe ingredients that were in drugs that have been removed from the market, or compounds that have not been adequately studied in humans.

“When the product contains a drug or other ingredient which is not listed as an ingredient we become especially concerned about the safety of the product,” says James P. Smith, M.D., an acting deputy director in FDA’s Office of Drug Evaluation.

To read more about the good, the bad and the ugly about weight loss programs, visit the FDA site.