Melatonin and sleep: can a supplement help?

Melatonin and sleep are inseparably linked: this hormone, produced by the pineal gland, signals to your body when it is time to rest by regulating the circadian rhythm. In recent years, melatonin supplements have become one of the most-purchased sleep health products, but consumers face an important question – is a supplement actually justified, and when?

How does melatonin regulate sleep?

Melatonin is a hormone produced by the pineal gland (epiphysis) when darkness falls. Its concentration in the blood rises at sunset, peaks in the middle of the night and drops sharply under the influence of morning light. Melatonin does not cause direct drowsiness the way sedatives do – instead, it shifts the body’s internal clock, letting the body know that the biological night has arrived.

According to studies, exogenous melatonin – that is, melatonin administered from outside the body – shortens the time it takes to fall asleep by an average of 7 minutes and improves total sleep duration in people with primary sleep disorders (Ferracioli-Oda et al., 2013). It is important to understand that this effect depends heavily on timing and dose – melatonin taken at the wrong time of day can instead shift the circadian rhythm in unwanted directions.

When is a melatonin supplement worth considering?

Melatonin supplements are backed by evidence in three main situations:

1. Time zone change (jet lag) – systematic reviews show that melatonin taken close to bedtime at your destination significantly relieves jet lag symptoms (Herxheimer & Petrie, 2002). The European Food Safety Authority (EFSA) has also approved the claim that 1 mg of melatonin helps reduce jet lag symptoms.
2. Shift work – for night workers, melatonin helps deepen daytime sleep, supporting better recovery (Buscemi et al., 2006).
3. Delayed sleep phase syndrome (DSPS) – young people who chronically find it hard to fall asleep before midnight gain evidence-based benefit from melatonin.

By contrast, in chronic insomnia caused by anxiety, chronic pain or poor sleep hygiene, melatonin’s effect is modest. For sleep disorders, the World Health Organization (WHO) recommends addressing the underlying causes first and applying behavioral interventions.

In a sports context, sleep is the cornerstone of recovery. Just as a creatine supplement supports muscle recovery and performance, adequate sleep quality – one regulator of which is melatonin – helps ensure that your training delivers the results you expect.

What dose of melatonin should you take, and when?

One of the most common mistakes is taking too large a dose. Most studies show that melatonin is effective at 0.5–1 mg, which already exceeds the physiological need (Brzezinski et al., 2005). Tablets on the market, however, are often 3–10 mg – many times more than necessary – which can cause morning drowsiness and paradoxically disrupt the circadian rhythm.

The Examine.com (2024) summary confirms that 0.5 mg is a sufficient effective starting dose for most adults – it has a shorter half-life and brings clearer morning alertness. Timing: take it 30–60 minutes before your intended bedtime. Just as the performance-enhancing supplement caffeine can block sleep when consumed late in the evening, melatonin timing also has to be planned carefully – taking it too early shifts the biological clock in an unwanted way.

What are the side effects of melatonin, and who should not take it?

Melatonin is generally safe for short-term use (2–4 weeks). The most common side effects include morning drowsiness (especially at higher doses), headache and dizziness (Zisapel, 2018). Pregnant women, breastfeeding mothers and people under 18 should consult a doctor before use, as long-term studies in these groups are lacking.

Sleep disorders can also have nutritional or lifestyle factors behind them. For example, some supplements are known to stimulate energy and mood regulation cascades, which in turn affect the circadian rhythm – similarly complex interactions are also covered in the Supplement 411: bitter orange review.

The topic of sleep and recovery is becoming more and more important in the sports and health community – this is also reflected in the Fitness.ee editorial team’s weekly news, where healthy lifestyle and recovery topics attract increasing reader attention.

Summary: who is melatonin right for?

Melatonin is a justified tool for regulating the circadian rhythm in specific situations – jet lag, shift work, DSPS. Start with a 0.5 mg dose, take it 30–60 minutes before bedtime and use it for no more than a few weeks in a row. In the case of chronic insomnia, deal with the underlying causes first and see a doctor if needed.

References

• Ferracioli-Oda E, Qawasmi A, Bloch MH (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. PMID: 23691095
• Herxheimer A, Petrie KJ (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev. PMID: 12076414
• Buscemi N et al. (2006). Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction. BMJ. PMID: 16391001
• Brzezinski A et al. (2005). Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Medicine Reviews. PMID: 15649737
• Zisapel N (2018). New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. British Journal of Pharmacology. PMID: 29318587

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