Melatonin is a hormone primarily produced in the pineal gland, located deep in the brain. It is best known for regulating the sleep-wake cycle, but its influence extends far beyond sleep.
Melatonin acts as a circadian signal, telling the body when it’s time to rest and also functions as a powerful antioxidant and regulator of immune and metabolic functions. As such, it plays an important role in healthy aging, disease prevention and cellular repair.
How melatonin works
Melatonin is secreted in response to darkness, beginning in the evening and peaking during the night. Light exposure, especially blue light, suppresses its production. This makes melatonin a key player in aligning the circadian rhythm with the environment.
It
binds to receptors in the brain and body that influence sleep, hormone release and immune responses. It helps prepare the body for sleep by lowering core temperature, reducing alertness and synchronizing various biological rhythms for nighttime recovery.
Functions of melatonin
Melatonin supports a wide range of physiological functions:
- Regulates sleep: supports sleep onset, quality, and circadian alignment;
- Protects cells: acts as a scavenger of free radicals and reduces oxidative stress;
- Modulates immune function: enhances immune defense while controlling inflammation;
- Supports detoxification and repair: facilitates tissue repair and mitochondrial function during rest;
- Influences metabolism: impacts insulin sensitivity, body weight and metabolic regulation.
These roles make melatonin vital not just for daily function, but also for long term vitality and healthspan.
Sources of melatonin
1. Natural production
- Synthesized from tryptophan, an amino acid, via serotonin in the pineal gland;
- Stimulated by darkness and suppressed by light, especially at night.
2. Dietary Sources
- Naturally found in small amounts in foods like:
- Tart cherries, tomatoes, grapes, walnuts, oats, rice and bananas.
3. Supplements
- Widely available in pill, liquid or spray form;
- Used for managing sleep disorders, jet lag and circadian rhythm disruption;
- Lower doses (0.3–1 mg) often mimic natural levels better than high doses.
Supplementation should be timed appropriately (typically 30–90 minutes before bedtime) and used under professional guidance when long-term.
Melatonin and longevity science
Melatonin’s role in circadian alignment, oxidative defense and immune regulation places it at the intersection of many longevity mechanisms:
- Neuroprotection: protects neurons from oxidative and inflammatory damage;
- Circadian synchronization: supports hormonal balance, metabolism and detoxification;
- Inflammaging control: modulates inflammatory pathways that accelerate aging;
- Mitochondrial health: supports energy production and cellular recovery.
Animal studies suggest melatonin may extend lifespan and in humans, it is being studied for its role in reducing the risk of Alzheimer’s, cardiovascular disease and immune decline.
Melatonin is more than a sleep hormone, it’s a key regulator of biological rhythms, repair and defense systems. With its antioxidant, anti-inflammatory and circadian regulating properties, melatonin plays a valuable role in promoting resilience, mental clarity and healthy aging.
Protecting and optimizing melatonin, through light hygiene, regular sleep and nutritional support, can enhance quality of life and support longevity from the inside out.
