Many doctors also say that Byetta is probably inappropriate as a weight-loss drug.

Does all this mean there are no useful, safe weight-loss drugs?

What are the risks of weight-loss drugs or surgery?

It was studied as a potential weight-loss drug, but failed to show benefit in clinical trials.

And it has also shown promise as a weight-loss drug.

This is the first time that a weight-loss drug has been permitted to treat overweight children.

At stake is a piece of the estimated $15 billion annual market for weight-loss drugs and products.

Moreover, other weight-loss drugs have turned sour, casting a shadow on the entire field.

But some experts say the study shows that leptin failed as a weight-loss drug.

"He started off by marketing a single weight-loss drug," said Rizzoli.