🌙Melatonin
Far more than a sleep hormone — melatonin is one of the most potent antioxidants produced by the human body, with clinical evidence for improving sleep onset and quality, reducing jet lag, supporting immune function and demonstrating anti-cancer properties through its antioxidant and hormone-modulating mechanisms.
What It Is
Melatonin is a hormone produced primarily by the pineal gland from serotonin during darkness, serving as the body's primary circadian rhythm signal. Its production begins 2-3 hours before natural sleep onset, peaks between 2-3 AM, and declines toward dawn — communicating to every cell in the body that it is nighttime and time to shift into rest-and-repair mode.
Beyond its circadian role, melatonin is one of the most potent antioxidants produced by the body — and unlike most antioxidants, it crosses the blood-brain barrier and every other cellular barrier, providing antioxidant protection in all compartments including mitochondria where other antioxidants cannot reach. Melatonin production declines dramatically with age — a 70-year-old produces approximately 75% less melatonin than a young adult — contributing to the sleep deterioration and increased oxidative stress associated with aging.
Nutritional Highlights
Health Benefits
- Meta-analyses confirm melatonin reduces time to fall asleep by 7-12 minutes and increases sleep duration
- Particularly effective for circadian rhythm disruptions — jet lag, shift work, delayed sleep phase disorder
- Lower doses (0.5-1mg) are often as effective as higher doses and cause less morning grogginess
Why it works: Melatonin works by signaling through MT1 and MT2 receptors in the suprachiasmatic nucleus — the brain's master clock — and in peripheral tissues, synchronizing the circadian rhythm toward sleep. It reduces core body temperature and shifts other circadian markers (cortisol, body temperature) toward sleep-compatible patterns, creating ideal conditions for sleep initiation.
- Most effective supplement for jet lag prevention — reduces jet lag severity and duration in multiple RCTs
- Timing relative to travel direction matters — taken at destination bedtime helps shift the circadian clock
- Effective for shift workers to shift sleep timing to unusual schedules
Why it works: Melatonin taken at the destination's bedtime provides a circadian signal to the brain that overrides the current circadian phase — accelerating adaptation to the new time zone. Randomised trials consistently find melatonin the most effective intervention for jet lag, reducing both the severity and duration of symptoms compared to placebo.
- One of the most potent endogenous antioxidants — can cross all cellular membranes including mitochondria
- Uniquely scavenges both reactive oxygen and reactive nitrogen species
- Stimulates antioxidant enzyme production through NRF2 pathway activation
Why it works: Melatonin's antioxidant mechanism is more comprehensive than most exogenous antioxidants — it directly neutralizes hydroxyl radicals, hydrogen peroxide and peroxynitrite, and stimulates superoxide dismutase, catalase and glutathione peroxidase production. Its ability to enter mitochondria (where most free radicals are generated) gives it antioxidant access that vitamins C and E lack.
- MT1 and MT2 receptors on immune cells allow melatonin to directly modulate immune function
- Enhances natural killer cell activity and T-cell proliferation
- Associated with reduced infection severity — natural nighttime peak coincides with peak immune repair activity
Why it works: The immune system's most active repair phase occurs during sleep — synchronized with the melatonin peak. Melatonin activates MT1 and MT2 receptors on T-cells, B-cells and natural killer cells, enhancing immune surveillance and activity during the night. This explains why sleep deprivation severely impairs immune function — partly through melatonin disruption.
- Melatonin inhibits cancer cell proliferation and induces apoptosis in multiple cancer types
- Reduces the estrogen-stimulated growth of hormone-sensitive breast cancer cells
- Regular night-shift work (disrupting melatonin) is classified as a probable carcinogen by IARC
Why it works: Melatonin's anti-cancer mechanism combines direct effects (inhibiting cancer cell proliferation, inducing apoptosis, blocking angiogenesis) with indirect effects (antioxidant protection of DNA from carcinogenic mutations). The IARC classification of night-shift work as a probable carcinogen is based largely on the cancer risk associated with chronic melatonin disruption.
- Melatonin concentrates in mitochondria — the primary site of free radical generation
- Protects mitochondrial DNA from oxidative damage that drives cellular aging
- Supports mitochondrial membrane integrity and electron transport chain efficiency
Why it works: Mitochondria both generate and are damaged by free radicals during normal energy production. Melatonin's unique ability to accumulate in mitochondria positions it as the primary antioxidant defender of the organelles most vulnerable to oxidative damage. Mitochondrial melatonin decline with age may contribute to the reduced mitochondrial function and efficiency associated with cellular aging.
How to Use It
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Safety & Considerations
- Most people use far too high a dose — 0.5-1mg is often as effective as 5-10mg with fewer side effects
- Higher doses can cause morning grogginess, vivid dreams and rebound insomnia
- Not for use during pregnancy without medical supervision
- May interact with blood thinners, immunosuppressants and diabetes medications
- Generally safe for short-term use — long-term safety is less studied; use the lowest effective dose
This content is for informational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional before making changes to your diet, supplement use, or treatment plan.
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