Leptin - a slimmer's dream that crashed?

The hopes of millions of obese persons were raised in 1994 when the "fat-melting" hormone leptin was discovered by Friedman and colleagues. Primary experiments on the adipose-tissue-derived hormone leptin seemed very promising and gave new life to obesity research. Drug companies also weathered profit and the human version of leptin was licensed to the biotech firm Amgen Inc. for an initial fee of $20 million. But is leptin the drug obese individuals have long waited for or is it just an illusion? This review will try to summarise current data on the role of leptin in body weight regulation.