Metabolife is a dietary supplement used to control appetite and facilitate weight loss. The supplement's main ingredient is Ephedra (active ingredient: ephedrine), and has been linked to serious side effects including seizures, heart attacks, and death. Ephedra is derived from an Asiatic shrub and is a stimulant that acts on the central nervous system to relax bronchial tubes.

On August 15, 2002, The Justice Department announced that it started a criminal investigation into whether Metabolife International lied about the safety of its long-controversial dietary supplement.

A few hours after news that a federal investigation into Metabolife was made public, Metabolife announced it would finally give the FDA the 13,000 complaints it has received since 1997. Of these complaints, 80 involved deaths, seizures, heart attacks, or other serious events.

Dr. Lester Crawford, then-acting commissioner of the FDA, found that "there is even more concern than when we started the investigation three weeks ago; now they have come forward with at least 80 serious adverse event reports. We still have Americans who are consuming this product, and allegedly vital information is being withheld from us, and we are reaching the end of our tethers."