Do melatonin supplements really help people sleep? Millions of jet-lagged and sleep-deprived Americans--citing countless self-help articles--insist they do. But the scientific evidence has been slim. There's no question that the hormone helps the brain tell a.m. from p.m.--regulating sleep cycles and circadian timing--when it is produced naturally by the body at night. What was lacking was clear evidence that taking melatonin in supplement form had the same sleep-inducing effect.
That's why there's so much interest in a study in the current issue of the journal Sleep. Researchers at Brigham and Women's Hospital and Harvard Medical School set out to test melatonin's effects...