And these experts say the pathway to a truly effective obesity drug is being illuminated by the very hormone, leptin, that has proved so disappointing.

Tenmsnet glands are processed for a well-known anti obesity drug.

Medicare payments, not to mention more coverage by private insurers, could hasten the development of new obesity drugs.

The drugs were working far better than any approved obesity drug ever had, she said.

"This study is the largest and longest of an obesity drug ever," he said.

One nerve growth factor, instead of alleviating a disease, made people feel full, and is now being tested as an obesity drug.

From pharmaceutical giants to tiny start-ups, the industry is spending billions of dollars developing obesity drugs.

Merck has no obesity drugs on the market, but it is making the area a priority, said Janet Skidmore, a spokeswoman.

The anorectic effect of PYY could possibly be a future obesity drug.

Its early attempts at drugs for neurological diseases failed, and an obesity drug recently produced only small weight losses in a large clinical trial.