Melatonin

Melatonin is a hormone produced primarily by the pineal gland in the brain that regulates the body's sleep-wake cycle (circadian rhythm). Often called the 'sleep hormone,' melatonin doesn't directly induce sleep but rather signals to the body that it's time to prepare for sleep by promoting drowsiness, lowering body temperature, and shifting the body into nighttime physiology. Melatonin production is controlled by light exposure — darkness stimulates its release, while light suppresses it.

Melatonin secretion follows a predictable daily pattern: levels begin to rise in the early evening (typically 2-3 hours before your natural bedtime), peak during the middle of the night, and decline toward morning as light exposure increases. This pattern is synchronized primarily by the suprachiasmatic nucleus (SCN) in the brain, which receives light information from the retina. Blue light from screens and artificial lighting is particularly effective at suppressing melatonin production, which is why evening screen use can disrupt sleep onset.

Beyond sleep regulation, melatonin functions as a powerful antioxidant, supports immune function, influences reproductive hormone cycling, and may play roles in blood pressure regulation and neuroprotection. Melatonin supplements are among the most popular sleep aids worldwide and are available over-the-counter in many countries, though in some European countries they require a prescription.

Melatonin supplementation is most evidence-supported for jet lag recovery, shift work sleep disorder, and delayed sleep phase disorder (difficulty falling asleep at conventional times). For general insomnia, the evidence is more modest, and melatonin is most effective for improving sleep onset latency (time to fall asleep) rather than total sleep duration.

If you're considering melatonin supplementation, start with the lowest effective dose (0.5-1 mg) taken 1-2 hours before desired bedtime. Melatonin is generally considered safe for short-term use but may interact with blood thinners, diabetes medications, immunosuppressants, and birth control. Prioritizing natural melatonin production through evening light hygiene is the preferred first approach.