Allergy Research Group was the first to introduce melatonin into the U.S. market.
Melatonin, the primary hormone of the pineal gland, is a powerful "chronobiotic" that helps maintain the body's normal circadian rhythms. In individuals who have difficulty sleeping or who have altered circadian rhythms because of jet lag or night shift work, melatonin supplementation promotes the resynchronization of this cycle. Supplementation can also benefit those whose difficulty sleeping is caused by the aging-related decrease in the body's ability to synthesize melatonin from the amino acid tryptophan. Research indicates melatonin exerts its sleep-promoting efficacy by decreasing the amount of time needed to fall asleep, by promoting the ability to stay asleep, and by enhancing the depth of sleep.