The government warned consumers Thursday that some "herbal fen-phen" products being sold as substitutes for banned diet drugs may be dangerous.
The Food and Drug Administration advised HPF, a Travose, Pa., based manufacturer, that its Herbal Phen-Fen and Herbal Phen-Fen Stage 2 products violate federal law and may be seized as illegal drugs. FDA officials said they were considering action against other companies.
The diet drugs fenfluramine, the "fen" in the popular fen-phen diet combination, and its cousin, Redux, were banned in September after doctors discovered the drugs could damage heart valves.
Since then, dieters have flocked to herbal blends.
There is no evidence the dietary supplements contained in such remedies _ mostly ephedrine and St. John's wort _ are effective for weight loss, the FDA said.
Worse, the agency said, ephedrine can cause dangerous side effects that range from high blood pressure and insomnia to seizures, heart attacks and stroke. Ephedrine also is sold under the names ephedra and ma huang.
The FDA acknowledged that it has no reports of side effects from St. John's wort or another herbal fen-phen product, 5-hydroxy tryptophan. But it warned consumers that neither product has been properly studied and said the tryptophan was related to a dietary supplement banned in the 1980s after it was linked to a fatal blood disorder.
The FDA ordered HPF to explain within 15 days how it would correct the violations.
HPF spokesman Michael Sands said the company is not "violating any applicable laws."