Melatonin Tolerance: No Evidence It Exists?
Melatonin is a hormone endogenously secreted by the pineal gland at night/evening and regulates one’s circadian rhythm (i.e. sleep-wake cycle) via interaction with melatonin receptors in the brain. Melatonin also: regulates blood pressure; interacts with the immune system; and acts as a potent antioxidant (scavenging free radicals). It has been thought that melatonin production decreases …