Melatonin is a hormone primarily known for regulating the sleep-wake cycle in vertebrates. Produced by the pineal gland in darkness, it signals the body to prepare for sleep, earning it the nickname "the hormone of darkness". Conversely, light exposure decreases melatonin production, promoting wakefulness. In humans, approximately 30 micrograms of melatonin are produced daily, with 80% of that amount occurring at night. Beyond sleep, melatonin also plays a role in blood pressure regulation and controlling seasonal rhythms, such as reproduction and hibernation in some animals.
While the body produces melatonin naturally (endogenous melatonin), it can also be synthesized in a lab and sold as a dietary supplement (exogenous melatonin). Supplementation is commonly used to address insomnia, jet lag, and circadian rhythm disorders. However, research indicates that melatonin supplements might only reduce the time it takes to fall asleep by a small margin. Andrew Huberman often recommends prioritizing behavioral tools like consistent light exposure and sleep schedules before considering melatonin supplements. It is important to note that melatonin supplements can interact with other medications, including blood pressure drugs, diabetes medications, and anticonvulsants.
