Amino Acids

Melatonin

N-acetyl-5-methoxytryptamine

Strong

Melatonin is a hormone produced by the pineal gland in response to darkness and is a key regulator of the sleep–wake cycle. Beyond sleep, it is a powerful antioxidant and immunomodulator with neuroprotective properties. Supplemental melatonin is widely used for insomnia, jet lag, and circadian rhythm disorders.

How It Works

Melatonin works through multiple mechanisms:

Circadian Rhythm: Binds to MT1 and MT2 receptors in the suprachiasmatic nucleus, signaling darkness and helping to synchronize sleep–wake cycles.
Sleep Induction: Lowers core body temperature, promotes drowsiness, and reduces alertness, facilitating sleep onset.
Antioxidant: Direct free-radical scavenger (more potent than vitamin E in some systems) and inducer of antioxidant enzymes.
Immune Modulation: Enhances aspects of immune function and exerts anti-inflammatory effects.
Neuroprotection: Protects mitochondria and may reduce neuroinflammation and excitotoxicity.

Natural Food Sources

Food	Amount per Serving
Tart cherries	0.01 mg per serving
Walnuts	0.0025 mg per serving
Walnuts	Trace amounts
Tomatoes	Trace amounts

Safety Information

Contraindications

Autoimmune disorders – melatonin can stimulate immune activity
Depression - may worsen in some individuals
Depression – may worsen symptoms in some individuals

Potential Side Effects

Next-morning drowsiness (especially at higher doses) (common)
Vivid dreams (common)
Vivid dreams or changes in dream patterns (uncommon)
Headache (uncommon)

Scientific Research

Melatonin for Primary Sleep Disorders: A Meta-Analysis

PLoS ONE

This large review confirmed that melatonin supplements help people fall asleep faster (about 7 minutes sooner) and improve sleep quality. Importantly, unlike many sleep aids, people don’t seem to build tolerance to melatonin – it keeps working over time. While the improvements may seem small, they’re meaningful for people who struggle with sleep onset. Melatonin is particularly helpful for jet lag and for people whose natural melatonin production is reduced (like older adults).

meta analysis

Disclaimer: The information provided is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare provider before starting any supplement regimen.