Melatonin: A chronobiotic that not only shifts rhythms

Abstract

Today, a chronobiotic is defined as a substance capable of shifting the phase of the CTS and reentraining circadian rhythms that have been dissociated in the short-term, or desynchronized in the long-term. The most widely recognized chronobiotic is melatonin. Its phase-shifting effects have been studied extensively. Surprisingly, the synchronizing effects of exogenous melatonin in patients suffering from long-term desynchronization (such as shift workers or the elderly) have not yet been tested. The chief goal of this manuscript is to bring this characteristic of melatonin back into the spotlight and emphasize that melatonin is a chronobiotic with multiple time-dependent effects. Another important goal of this paper is to stress that melatonin is a potent drug whose nonprescription use may have serious general health consequences.