Scientists first realized that melatonin existed and was produced by the pineal gland back in 1917. Yet researchers were not able to isolate this hormone until the 1950s.

Why did it take them so long to discover melatonin? The pineal gland is very small. It weighs only about 100 mg in humans. And it does not produce very much melatonin. The typical adult male makes only 30 micrograms during an entire day. Also, the techniques available for isolating chemical compounds that were available during the early and mid-twentieth century were not very precise. It took a considerable amount of work for researchers to actually find melatonin.

Dr. Alan Lerner and his coworkers required pineal glands from 250,000 cows in order to come up with enough melatonin to be able to isolate and identify this hormone. Fortunately, modern researchers have much more precise technology. Nowadays, researchers can easily measure and compare...