When you're a pharmaceutical company hoping to turn a profit on a controversial product, your work never stops, it would appear. Although, I suppose that's true of any pharmaceutical company nowadays...

GlaxoSmithKline, marketers of the over-the-counter weight-loss drug alli, which we profiled in last month's issue, is asking the FDA to force weight-loss supplement sellers to conduct clinical trials on their products. With fewer supplements on the market, GSK would face significantly less competition for its product, which the company hopes to turn into a blockbuster.

Alli is the only weight-loss pharmaceutical available without a prescription. It's a lower-dose of Xenical, a prescription-only drug sold by Roche. It works by blocking the absorption of fat in the intestine. GSK licensed alli from Roche, then moved it into over-the-counter status.

Americans currently spend approximately $2 billion on nonprescription dietary supplements aimed at weight loss.

GSK filed its petition with the American Dietetic Association and two other health groups that receive financial support from the pharmaceutical company, according to the New Jersey Star-Ledger. The petition argues that consumers will think of supplements that help with weight loss as drugs that treat and prevent unhealthy conditions, and the products should therefore be treated like drugs.