Melatonin: Usage, Precautions, Alternatives

Introduction

Melatonin (N-acetyl-5-methoxytryptamine) is a neurohormone synthesized from serotonin in the pineal gland. Its secretion follows a precise circadian rhythm: rising about 2 hours before habitual bedtime (dim light melatonin onset), peaking between 2-4 AM, then gradually declining. Light — especially blue spectrum — inhibits its secretion.

Validated Indications

Jet Lag

Best-documented indication. Cochrane review (Herxheimer & Petrie, 2002): "remarkably effective" for jet lag across 5+ time zones. Dose: 0.5-5 mg at bedtime at destination, 2-5 days.

Delayed Sleep Phase

Common in adolescents. Low-dose melatonin (0.3-0.5 mg) taken 4-6 hours before desired bedtime progressively advances the circadian phase. This is a chronobiotic, not hypnotic, use.

Insomnia in Over-55s

Prolonged-release melatonin (Circadin, 2 mg) is approved for primary insomnia in over-55s. Improves sleep onset latency and quality without dependence.

Limitations

Melatonin is not a sleeping pill — it adjusts the biological clock. Buscemi et al. (2006) meta-analysis: minimal effect on sleep onset latency (-7 minutes average) in chronic insomnia. Paradoxical dose-response: high doses (5-10 mg) are not more effective than low doses (0.3-1 mg). Erland & Saxena (2017): 71% of supplements had different dosages than labeled.

Precautions

• Autoimmune diseases: immunomodulatory effects.
• Pregnancy and breastfeeding: insufficient data.
• Children: only under specialized medical advice.
• Drug interactions: anticoagulants, antidiabetics, immunosuppressants.

Natural Alternatives

• Morning light therapy: 10,000 lux for 20-30 minutes at waking.
• Dietary tryptophan: turkey, banana, nuts, pumpkin seeds, eggs.
• Magnesium: melatonin synthesis cofactor. 300-400 mg bisglycinate evening.
• Tart cherries (Montmorency): natural melatonin source (Howatson et al., 2012).
• Blue light reduction: simplest method to increase natural melatonin production.

Disclaimer

This article is for informational purposes only. Melatonin, even over-the-counter, is not harmless. Consult a healthcare professional before supplementation, especially for children, pregnant women or those on medication.