The Food and Drug Administration is cracking down on manufacturers of certain weight-loss, body-building and sexual-enhancement supplements that contain potentially dangerous ingredients.

The FDA said Wednesday that some manufacturers are deceptively labeling products to hide that they contain ingredients known to cause adverse health effects. Other supplements contain ingredients that should be available only by prescription.
“These tainted products can cause serious adverse effects, including strokes, organ failure and death,” said FDA Commissioner Margaret Hamburg. “The manufacturers selling these tainted products are operating outside the law.”

Dietary supplements can slip through the regulatory cracks because they do not have to be approved by the FDA. Manufacturers are responsible for making sure their products are safe.

In a letter to the supplement industry, the agency said manufacturers who distribute tainted products could face criminal prosecution.

The FDA said the agency is targeting weight-loss products containing sibutramine, which has been withdrawn from the market for causing increased risk of heart attack and stroke. The agency said it has discovered “dozens of products” that contain the ingredient, including those marketed under the brand names Slimming Beauty, Solo Slim and Slim-30.

Body-building products under scrutiny include those containing anabolic steroids or steroid analogs. The agency cited Tren Xtreme, ArimaDex and Clomed as supplements that have been labeled to contain those products.

The agency also warned consumers to be wary of sexual-enhancement products that include similar ingredients to the approved drugs Viagra, Cialis, and Levitra. Those ingredients should only be available by prescription. The FDA said products marketed under the names Vigor-25, Duro Extend Capsules for Men, Magic Power Coffee have been determined to be in violation of federal law.

“Consumers should avoid products marketed as supplements that claim to have effects similar to prescription drugs,” said Michael Levy, director of labeling compliance for the agency. “Consumers should also be wary of products with labeling only in a foreign language or that are marketed through mass e-mails.”