WASHINGTON – The Food and Drug Administration said Thursday it is setting up a new system for identifying potentially dangerous and mislabeled dietary supplements, and it promised to aggressively go after companies that sell misleadingly labeled products.

Responding to criticism that the government has responded too slowly to the dangers posed by popular supplements such as ephedra and androstenedione – which were both taken off the market in the past year because of health concerns – the FDA outlined a new regulatory scheme for overseeing the fast-growing supplement industry.

In addition to upgrading its process for collecting “signals” of possible harmful effects in people using supplements, the FDA also set its first standard for determining whether the claims on labels are properly substantiated. From now on, supplement makers will have to show “competent and reliable scientific evidence” to back up their health claims, it said.

An estimated 1,000 dietary supplement companies sell 29,000 products, but since passage of the 1994 Dietary Supplement Health and Education Act, the industry has been largely free of government oversight.