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Melatonin
Melatonin is a hormone naturally produced by the pineal gland that regulates the sleep-wake cycle. Supplemental melatonin is widely used to improve sleep onset, quality, and circadian rhythm alignment - with emerging evidence for neuroprotective and antioxidant benefits.
Benefits
What is Melatonin?
Melatonin (N-acetyl-5-methoxytryptamine) is a hormone produced by the pineal gland in response to darkness. It is the body's primary timekeeper, signalling to the brain and body that it is time to sleep. Melatonin levels naturally rise in the evening, peak during the night, and fall in the early morning hours.
As a supplement, melatonin is the most widely used sleep aid in the world. It is particularly effective for circadian rhythm disorders (jet lag, shift work, delayed sleep phase syndrome) and reducing the time it takes to fall asleep. Unlike pharmaceutical sleep aids, melatonin does not suppress REM sleep or cause significant next-day grogginess.
Beyond sleep, melatonin is a powerful endogenous antioxidant that crosses the blood-brain barrier. Emerging research highlights its neuroprotective properties, including potential benefits against neurodegeneration, oxidative stress, and immune dysregulation. Its role in cognitive health is increasingly recognised as quality sleep is essential for memory consolidation and brain waste clearance.
- Circadian rhythm regulation: Binds to MT1 and MT2 receptors in the suprachiasmatic nucleus (SCN) of the hypothalamus, the brain's master clock, to synchronise the sleep-wake cycle.
- Sleep onset promotion: MT1 receptor activation promotes sleepiness and reduces neuronal firing rate. MT2 activation shifts circadian phase timing.
- Antioxidant activity: Melatonin is a potent free radical scavenger - twice as effective as vitamin E at neutralising peroxyl radicals. It also stimulates production of other antioxidant enzymes (SOD, GPx, catalase).
- Neuroprotection: Reduces neuroinflammation, protects mitochondrial function, and may inhibit amyloid-beta aggregation associated with Alzheimer's disease.
- Immune modulation: Regulates immune cell activity and cytokine production, with both anti-inflammatory and immunostimulatory properties depending on context.
- For sleep onset: 0.5–3 mg taken 30–60 minutes before bed
- For jet lag: 0.5–5 mg at destination bedtime for 2–5 days
- For circadian disorders: 0.5–1 mg taken 2–4 hours before desired sleep time
- Less is more: Lower doses (0.3–1 mg) often work better than high doses. Supraphysiological doses (5–10 mg) may cause next-day grogginess and disrupt natural production.
- Extended release: Available in immediate-release and extended-release formulations - extended release helps with sleep maintenance
Melatonin should be taken in a dark environment for best results. Blue light exposure after taking melatonin will reduce its effectiveness.
- Side effects: Generally safe at recommended doses. Possible drowsiness, headache, dizziness, or vivid dreams.
- Next-day grogginess: Common with doses above 3 mg. Reduce dose if this occurs.
- Hormonal effects: May affect reproductive hormones at high doses or with long-term use. Not recommended for children without medical supervision.
- Drug interactions: May interact with blood thinners, immunosuppressants, diabetes medications, and contraceptives.
- Autoimmune conditions: Use with caution due to immune-modulating effects.
- Legal status: Over-the-counter supplement in the US. Prescription-only in the UK and much of Europe.
Natural Sources & Forms
- Endogenous production: Produced by the pineal gland in response to darkness. Production declines significantly with age.
- Food sources: Tart cherries, walnuts, tomatoes, rice, and barley contain small amounts of melatonin
- Supplements: Available as tablets, capsules, gummies, sublingual drops, and sprays. Synthetic melatonin is preferred for purity.
Research Studies
Frequently Asked Questions
Melatonin is a hormone naturally produced by the pineal gland that regulates the sleep-wake cycle. Supplemental melatonin is widely used to improve sleep onset, quality, and circadian rhythm alignment - with emerging evidence for neuroprotective and antioxidant benefits.
The key benefits of Melatonin include: Anxiety & Calm, Longevity, Mood, Sleep, Stress Relief.
Circadian rhythm regulation: Binds to MT1 and MT2 receptors in the suprachiasmatic nucleus (SCN) of the hypothalamus, the brain's master clock, to synchronise the sleep-wake cycle. Sleep onset promotion: MT1 receptor activation promotes sleepiness and reduces neuronal firing rate. MT2 activation shifts circadian phase timing. Antioxidant activity: Melatonin is a potent free radical scavenger - twice as effective as vitamin E at neutralising peroxyl radicals. It also stimulates production of other antioxidant enzymes (SOD, GPx, catalase). Neuroprotection: Reduces neuroinflammation, protects mitochondrial function, and may inhibit amyloid-beta aggregation associated with Alzheimer's disease. Immune modulation: Regulates immune cell activity and cytokine production, with both anti-inflammatory and immunostimulatory properties depending on context.
For sleep onset: 0.5–3 mg taken 30–60 minutes before bed For jet lag: 0.5–5 mg at destination bedtime for 2–5 days For circadian disorders: 0.5–1 mg taken 2–4 hours before desired sleep time Less is more: Lower doses (0.3–1 mg) often work better than high doses. Supraphysiological doses (5–10 mg) may cause next-day grogginess and disrupt natural production. Extended release: Available in immediate-release and extended-release formulations - extended release helps with sleep maintenance Melatonin should be taken in a dark environment for best results. Blue light exposure after taking melatonin will reduce its effectiveness.
Side effects: Generally safe at recommended doses. Possible drowsiness, headache, dizziness, or vivid dreams. Next-day grogginess: Common with doses above 3 mg. Reduce dose if this occurs. Hormonal effects: May affect reproductive hormones at high doses or with long-term use. Not recommended for children without medical supervision. Drug interactions: May interact with blood thinners, immunosuppressants, diabetes medications, and contraceptives. Autoimmune conditions: Use with caution due to immune-modulating effects. Legal status: Over-the-counter supplement in the US. Prescription-only in the UK and much of Europe.
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