WASHINGTON, DC -- Some dietary supplements for weight loss and bodybuilding may have undeclared or deceptively labeled ingredients, according to the Food and Drug Administration (FDA). The substances include the active ingredients in FDA-approved drugs or closely related drugs, or other compounds, such as novel synthetic steroids that do not qualify as dietary ingredients.

In recent years, the FDA has alerted consumers about nearly 300 tainted products marketed as dietary supplements and received numerous complaints of injury associated with these products.

“These tainted products can cause serious adverse effects, including strokes, organ failure and death,” FDA Commissioner Margaret A. Hamburg said in a release. “The manufacturers selling these tainted products are operating outside the law.”

The FDA has noted the three most common categories of these illegal products are:

  • Weight loss products containing active ingredients, such as sibutramine. Sibutramine is the active ingredient in the drug Merida, which was recently withdrawn from the market due to increased risk of heart attack and stroke. The FDA has discovered dozens of products that contain sibutramine or closely related drugs, according to the government agency.
  • Body-building products containing anabolic steroids or steroid analogs. These products can cause acute liver injury and increase the risk for heart attack, stroke and death. Products such as Tren Xtreme, ArimaDex and Clomed have been labeled to contain either anabolic steroids or aromatase inhibitors, which prevent anabolic steroids from being converted to estrogen.
  • Sexual enhancement products that contain the same or closely related active ingredient of the active ingredient in the approved drugs Viagra, Cialis and Levitra.

“The labeling of these tainted products may claim that they are ‘alternatives’ to FDA-approved drugs, or ‘legal’ alternatives to anabolic steroids,” said Michael Levy, director of the Division of New Drugs and Labeling Compliance at the FDA’s Center for Drug Evaluation and Research. “Consumers should avoid products marketed as supplements that claim to have effects similar to prescription drugs. Consumers should also be wary of products with labeling only in a foreign language or that are marketed through mass e-mails.”

The FDA now has a new rapid public notification system (RSS feed) on its website to quickly warn about these products.