Melatonin is an essential hormone that plays a direct role in the body’s circadian rhythm, particularly in regulating the sleep–wake cycle. It has a significant impact on overall physical and mental health.
What is melatonin?
Melatonin is a hormone produced by the pineal gland in the brain. Its production increases at night when light levels fall and decreases during the day. It therefore acts as a “time signal”, telling the body when it is time to rest.
How is melatonin produced?
Melatonin is synthesised through the following pathway:
Tryptophan → 5-HTP (5-hydroxytryptophan) → Serotonin → Melatonin
- Tryptophan: an amino acid obtained from foods such as milk, nuts, bananas, and grains
- 5-HTP: formed from tryptophan via enzymatic processes
- Serotonin: a neurotransmitter involved in mood and a key precursor to melatonin
- Melatonin: the hormone responsible for regulating sleep
Supporting natural melatonin production
- Morning sunlight exposure: helps set the body clock accurately
- Avoid screens 1 hour before bed: or use blue-light filters
- Consume tryptophan-rich foods: such as bananas, milk, almonds, and soybeans
- Keep the bedroom dark: the darker the environment, the better melatonin is released
Key functions of melatonin
- Regulates sleep
Melatonin helps the body feel sleepy and fall asleep more easily. Abnormal levels may lead to insomnia. - Balances the circadian rhythm
Helps the body adjust to time changes, such as jet lag or shift work. - Antioxidant properties
Melatonin helps reduce cellular damage caused by free radicals, supporting anti-ageing processes and reducing inflammation. - Supports the immune system
Plays a role in enhancing immune function, particularly during sleep-related recovery processes.
Factors affecting melatonin secretion
- Light exposure: light from phones or computer screens at night can suppress melatonin production
- Age: melatonin production declines with age
- Sleep habits: irregular sleep patterns or late nights can disrupt hormone levels
How to increase melatonin naturally
- Avoid blue light before bedtime (e.g. from mobile devices)
- Maintain a consistent sleep schedule
- Dim the lights before going to bed
- Exercise regularly
- Eat foods that support production, such as bananas, milk, and almonds
Summary
Melatonin is a crucial hormone for sleep quality and overall health. Maintaining healthy lifestyle habits—such as getting adequate sleep and reducing light exposure at night—can support optimal melatonin production and promote long-term wellbeing.
Dr. Apakorn Poltian (Medical Technologist)
Reference
- Arendt, J. (2008). Melatonin and human rhythms. Chronobiology International, 25(2–3), 325–330.
- Claustrat, B., & Leston, J. (2015). Melatonin: Physiological effects in humans. Neurochirurgie, 61(2–3), 77–84.
- Hardeland, R. (2012). Melatonin in ageing and disease—Multiple consequences of reduced secretion, options and limits of treatment. Aging and Disease, 3(2), 194–225.
- National Institutes of Health (2022). Melatonin: What you need to know.
- Pandi-Perumal, S. R., et al. (2006). Melatonin: Nature’s most versatile biological signal? FEBS Journal, 273(13), 2813–2838.
- Reiter, R. J., et al. (2014). Melatonin as a mitochondria-targeted antioxidant: One of evolution’s best ideas. Cellular and Molecular Life Sciences, 71(19), 3737–3751.
