The FDA is advising consumers to use "extreme care" when purchasing online products that claim to diagnose, treat or prevent the H1N1 swine flu virus.
Among the so-called fake products that received warnings from the Food and Drug Administration was an ultraviolet light that promised to "destroy swine flu virus." There was also a dietary supplement claiming to be "more effective than the swine flu shot."
Experts say marketers take advantage of people who are fearful.
"It's very important that consumers know these products can be deceptive and risky," said Alyson L. Saben, deputy director of FDA's Office of Enforcement. "They offer a false sense of protection and could delay someone from seeking treatment."
Tamiflu -- one of two antiviral drugs approved by the FDA for treating swine flu -- was being offered by online pharmaceutical retailers. One came in an envelope postmarked from India and consisted of two white tablets found to contain talc and acetaminophen, authorities said.
The active ingredient in Tamiflu is oseltamivir, which was not found in that particular product.
Weil Lifestyle LLC, the online store featuring nationally-known natural health guru Dr. Andrew Weil, was sent a warning regarding its vitamin packs and immune support formula. Weil said the language that concerned the FDA was removed and that he supported the agency's efforts. He also said the website information was "primarily educational."
Officials say about 82 percent of the cited retailers have complied, but enforcement actions are being considered against several who ignored the warnings.
The FDA and the Federal Trade Commission continue to closely monitor questionable swine flu products.