The importance of sleep hardly needs emphasising. Sleep deprivation leads to obvious consequences such as fatigue and a dull complexion, but also to lesser-known effects including weight gain and impaired cognitive function. The tendency to fall asleep is something every person shares regardless of age, though its intensity varies from individual to individual. Everything depends on melatonin — the hormone that signals the body to rest as daylight fades. This is why melatonin is often called the sleep hormone or the hormone of the night. But what influences its levels, and how can you address a potential deficiency?
How Melatonin Is Produced
Melatonin is a hormone produced naturally by the human body. It is synthesised by the pineal gland through a mechanism of autoregulation and negative feedback. However, the pineal gland does not act alone — the nervous system plays an equally important role. Specifically, neurons along the visual pathway are responsible for receiving light stimuli from photoreceptors in the retina of the eye. The degree to which these neurons are stimulated directly regulates the activity of the pineal gland.
Melatonin production occurs almost exclusively in darkness, triggered by sympathetic nerve fibres. When too much light reaches the eyes, melatonin production drops, leading to lower concentrations in the blood. Crucially, this applies not only to natural light but also to artificial sources — screens from smartphones, computers, and televisions all suppress melatonin synthesis. This is a key reason why many people today experience a growing disconnect between their internal biological clock and the natural day-night cycle, resulting in sleep disturbances and difficulty falling asleep.
[tip:To support natural melatonin production, reduce screen exposure at least one hour before bedtime. If that is not possible, consider using blue light filters or night mode on your devices.]
Melatonin — Properties and Effects
Melatonin's primary role is synchronising the body's circadian rhythm with the 24-hour day-night cycle. It determines when the body works and when it rests, which is directly linked to fluctuations in blood melatonin levels throughout the day. The highest concentrations occur at night, peaking between midnight and 3:00 AM, while daytime levels remain significantly lower. This cycle is what enables melatonin to facilitate falling asleep, reduce the number of night-time awakenings, and improve overall sleep quality.
Beyond sleep regulation, melatonin also possesses notable antioxidant properties, helping to neutralise free radicals and protect cells from oxidative damage. For those interested in antioxidant support, melatonin is just one of many compounds that contribute to the body's defence system — you can explore a broader range in our sleep support collection.
A lesser-known property of melatonin is its influence on the endocrine system, particularly gonadotropic hormones. These hormones are responsible for the proper development of the gonads and for regulating the menstrual cycle. In other words, melatonin plays a role in menstrual regularity. Its influence on the gonads also extends to the timing of puberty — an observation that has become increasingly relevant in the modern era, where children raised with constant exposure to screens and artificial light tend to reach puberty earlier than previous generations.
[note:Melatonin does more than regulate sleep. Its antioxidant and hormonal properties make it a multifunctional hormone with effects across several body systems.]
Melatonin Spray — How to Use It
Melatonin spray is an aerosol formulation packaged in a compact bottle with an atomiser. These products were designed with travellers in mind — people who frequently cross time zones and struggle with jet lag. Thanks to the convenient format, a melatonin spray fits easily into hand luggage or even a pocket, making it accessible whenever needed.
Depending on the product, as little as 1 mg sprayed shortly before bedtime may be enough to help ease the effects of jet lag or other factors that make falling asleep difficult. The spray is applied by misting it inside the oral cavity. The number of sprays per dose varies between products, so always check the manufacturer's recommended dosage before each use. Remember to shake the product before every application.
Melatonin — At What Age Is It Appropriate?
Most melatonin product labels and information leaflets clearly state that the supplement should not be used by children, pregnant women, or breastfeeding mothers. However, some research suggests that melatonin may be beneficial for children aged 3–15 who experience neurodevelopmental disorders, sleep disturbances, difficulty falling asleep, frequent night-time awakenings, or reduced total sleep time. Any such use in children must be conducted under strict supervision of a specialist physician — self-administration is not recommended.
[warning:Never give melatonin supplements to children without consulting a paediatrician or sleep specialist first. Dosage and duration must be carefully monitored by a healthcare professional.]
Melatonin — Levels and Dosage
Natural melatonin production fluctuates throughout the day in line with the circadian rhythm, but it is also significantly influenced by age. Normal peak melatonin concentrations vary across life stages:
- Children — approximately 250 pg/ml
- Adolescents — 120–180 pg/ml
- Adults — 70–80 pg/ml
- Seniors (65+) — 20–30 pg/ml
This age-related decline explains why older adults tend to have greater difficulty falling asleep and generally require less sleep than children. Supplementation can help compensate for this natural decrease.
Recommended dosages depend on the specific situation:
- General sleep difficulties — 0.5 to 3 mg, approximately one hour before bedtime
- Jet lag (crossing time zones) — up to 5 mg before sleep at the destination
- Shift work — 1 to 3 mg before daytime sleep following a night shift
- Age-related sleep quality decline — 1 to 3 mg before bedtime
It is worth noting that synthetic melatonin typically reaches its full effectiveness after approximately two weeks of regular use.
[tip:Start with the lowest effective dose — often 0.5 to 1 mg — and increase gradually if needed. More is not always better with melatonin; excessive doses can actually disrupt sleep quality.]
Explore our selection of melatonin supplements, available in tablets, capsules, liquid drops, and convenient oral sprays:
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Melatonin — Contraindications
Although melatonin is a hormone naturally produced by the body, its synthetic form is not suitable for everyone. Supplementation should be avoided by pregnant women, children (unless prescribed by a specialist), individuals who consume alcohol regularly, those with liver conditions, and anyone with a known allergy to synthetic melatonin.
It is also advisable to taper off melatonin gradually once the desired results have been achieved, rather than stopping abruptly.
For those who cannot or prefer not to use synthetic melatonin, natural approaches can help support the body's own production. Maintaining a consistent bedtime, aiming for around eight hours of sleep, and avoiding screens before bed are foundational habits. Eating calming foods in the evening — such as fish, chicken breast, or yoghurt — may also be supportive. Regular daily walks and exposure to natural daylight during the day help reinforce the circadian rhythm. These methods may not be as immediately effective as supplementation, but they represent a safe and sustainable alternative.
Whether you choose supplementation or natural methods, the goal is the same — supporting your body's ability to fall asleep, stay asleep, and wake feeling rested. For a wider range of products that support restful sleep, explore the brain and cognitive health section at Medpak.
Key Takeaway: Melatonin is the body's natural sleep hormone, with production peaking at night and declining with age. Supplementation in the range of 0.5–5 mg can support sleep quality, ease jet lag, and help shift workers — but should always be used responsibly, starting with low doses and with awareness of contraindications.
