The products, promoted for building muscle and increasing strength, may cause serious long-term health problems, the Food and Drug Administration said Thursday.
The agency said that anyone who has bought the products to stop taking them and return them to their place of purchase.
The agency issued warning letters for:
Among the problems the FDA said are associated with anabolic steroids are liver toxicity; testicular atrophy and male infertility; masculinization of women; breast enlargement in males; short stature in children; harmful cholesterol levels; and potentially higher risks of heart attack and stroke.
A man who answered the phone at Affordable Supplements and declined to give his name said he could not comment. Legal Gear had no telephone listing. Messages left with Anabolic Resources and Supplements To Go were not immediately returned.
The action came on the same day that a consumer expert told the House Government Reform Committee that dietary supplements should undergo safety testing before being allowed on the market.
The 1994 law that allows supplements to be sold without government approval "created serious regulatory loopholes that have opened the floodgates to thousands of untested dietary supplement products," Janell Mayo Duncan of Consumers Union said.
Examples of dietary supplements include vitamins, minerals, amino acids, herbs and botanical products. Supplements have grown to a $20 billion market in the United States, C. Lee Peeler of the Federal Trade Commission told the committee.
While many supplements are safe and useful, Duncan said the absence of FDA supervision has resulted in a growing number of questionable products that would not be allowed on the market if they had been subject to safety testing.
Duncan urged that supplement makers be required to advise the FDA if they become aware of serious problems associated with their products.
Peeler noted that the FTC has filed more than 100 actions over the past decade challenging false of unsubstantiated claims for supplements.