Melatonin: Usage, Precautions, Alternatives
Melatonin, the 'sleep hormone' secreted by the pineal gland in response to darkness, plays a central role in regulating the sleep-wake cycle. Its supplemental use has grown considerably, but its indications, limitations and precautions remain often misunderstood. This article reviews scientific evidence, dosages, formulations, contraindications and natural 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.
Medical Disclaimer
The information presented in this article is provided for educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment prescription. If in doubt, always consult your physician or a qualified healthcare professional. The techniques described do not replace conventional medical treatment.