Melatonin and sleep: its role and ways to support it

Melatonin is often called the sleep hormone, but its main job is to tell the body that night has arrived. The role of melatonin in sleep is primarily to work with the brain’s internal clock, organising the daily rhythm of alertness, rest and other functions. Produced by the pineal gland in response to darkness, it is closer to a timing signal than a switch that forces someone to sleep. Understanding that distinction helps explain why melatonin can be useful for some sleep problems yet disappointing for others.

For most people, a steady routine and good sleep habits do more to improve sleep than taking a supplement. Light exposure, meal and caffeine timing, activity, bedroom conditions and stress all influence the body clock. Natural support also depends on individual health, age and medication. In Australia, where work shifts, long urban commutes and changing daylight-saving times can complicate body timing, using melatonin responsibly means matching it to the underlying schedule rather than treating it as a general cure for tiredness.

How melatonin works in the body

Melatonin release rises during the biological evening and remains elevated through the night, with the pattern varying between people. The suprachiasmatic nucleus, a cluster of nerve cells in the hypothalamus, uses the hormone alongside direct light signals from the retina to keep the body oriented to the 24-hour day. In a regular routine, melatonin prepares physiological systems for sleep and helps maintain a stable sleep-wake cycle.

Light has the strongest everyday influence on this system. Bright or prolonged light in the evening can suppress melatonin and delay the body’s readiness for sleep; morning light does the opposite and helps pull the clock forward. This is why melatonin is not simply something added when sleep will not come. Its value depends on when the body’s clock is sending its “night” signal and when a person needs to sleep.

Melatonin also acts on receptors involved in the sleep-wake cycle, so extra hormone can create sleepiness without correcting the underlying timing. People who take it at the wrong time may feel drowsy at an inconvenient hour or find that their sleep has shifted later. Individual responses vary, and older adults may produce less nighttime melatonin, yet taking more is not always better. Shift workers, frequent travellers and people with delayed sleep patterns may have a different response from someone experiencing ordinary insomnia.

What melatonin can and cannot do

Melatonin has the clearest evidence when sleep timing is out of step with the desired schedule. It can help reduce jet-lag symptoms when a small dose is taken near the destination’s bedtime, and it may help some adolescents or adults with delayed sleep-wake phase by moving sleep earlier. Shift workers may also use timed melatonin under guidance, although bright-light strategies and carefully planned naps are often needed as well. Results depend on correct timing, the direction of the schedule change and the person’s health.

For common chronic insomnia, melatonin is generally not a first-line treatment. A 2023 clinical insomnia guideline found that its effects on sleep are small, and evidence was not strong enough to recommend it for insomnia in adults without circadian timing problems. Cognitive behavioural therapy for insomnia, often called CBT-I, has more durable effects and addresses unhelpful thoughts, sleep scheduling and conditioned wakefulness. A clinician can distinguish these conditions because they may look similar but need different responses.

Melatonin also does not remove the effects of untreated sleep apnoea, restless legs, pain, reflux or the effects of some medicines. Alcohol may make a person feel sleepy sooner while fragmenting the second half of the night, so adding melatonin to a night of drinking can create grogginess without improving restorative sleep. Foods sometimes advertised as “high-melatonin”, including tart cherries, milk and certain seeds, contain the compound, but studies do not show that eating them reliably changes sleep duration or quality. Small kiwifruit studies have been promising, although the evidence remains limited and kiwifruit cannot be treated as a dependable melatonin substitute.

Australian routines that shape the sleep signal

Australian routines make the timing issue easy to overlook. A commuter in Sydney, Melbourne or Brisbane may leave home before dawn, travel for an hour or more and arrive at work under bright office lights, then use a phone during the evening. That pattern places light and stimulating information at both ends of the day. Someone working from home in Perth, however, may begin the day without the same early outdoor light, which matters because morning daylight is one of the strongest anchors for the body clock.

Daylight-saving changes add another layer. New South Wales, Victoria, Tasmania and South Australia shift their clocks seasonally, while Queensland, Western Australia and the Northern Territory do not. Moving the clock forward can make the evening feel darker sooner, but it also changes the relationship between work, meals and sleep. During southern summer, Perth can be three hours behind Sydney on the clock. People sensitive to this shift can protect their routine by keeping wake time stable and obtaining outdoor light soon after the change, rather than changing every part of the day at once.

The local retail market reflects how popular melatonin has become. Pharmacy shelves, health-food stores and major supermarkets may stock tablets, liquids or gummies, sometimes labelled “natural” and sometimes promoted for travel, stress or screen-related wind-down. These products are not interchangeable: strengths, release profiles and added ingredients vary. Under Australia’s Therapeutic Goods Act 1989, therapeutic goods are regulated by the Therapeutic Goods Administration. Many complementary medicines, including some melatonin products, are listed on the Australian Register of Therapeutic Goods and carry an AUST L number. Listing supports quality and safety oversight, but it does not mean every product is suitable for every sleep complaint.

Ways to support melatonin naturally

The most reliable natural support is regular light exposure soon after waking. Step outside for a short walk, sit near a window with a morning coffee, or walk part of the commute in Brisbane or Adelaide. Even on cloudy days, outdoor brightness is usually greater than indoor lighting. Keeping the wake time within a similar window each day helps anchor melatonin release, while morning light tells the brain that the biological night will end on time. Napping is best kept brief and earlier in the day when it is needed.

Evening light needs a gentler approach. Dim overhead and bedside lights, avoid very bright screens close to bedtime and use night or reduced-brightness settings on a phone or television. Screens are not uniquely harmful to melatonin; the more relevant issues are brightness, content and how long they occupy the attention. Australian homes also need to stay cool and dark during hot nights, particularly in Perth, Darwin and northern Queensland. Lightweight curtains, a fan, breathable bedding and a consistent room temperature can prevent heat from adding to the mental arousal of lying awake.

Regular activity, meals and caffeine can reinforce the signal too. Exercise most days, finish vigorous sessions a few hours before bed if they leave you stimulated, and keep the main caffeine intake earlier in the day. Coffee, energy drinks and some teas may contain substantial caffeine, so an afternoon pick-me-up can work against an early bedtime. A light evening meal is usually more comfortable than a heavy one, and relaxation rituals can lower mental arousal without pretending to increase melatonin directly. These habits support the clock’s overall timing rather than replacing it with one magic food or drink.

Practical steps for stronger sleep habits

The following habits offer a practical starting point for supporting sleep and melatonin timing without reaching immediately for a supplement. They work best as a consistent routine, and the most useful choice depends on the person’s work, health and main sleep difficulty.

• Fix a wake time and obtain outdoor morning light, even if the previous night was poor.
• Keep caffeine mostly to the morning and early afternoon, and track food, drinks and sleep in a diary.
• Reduce evening brightness and avoid stimulating or emotionally charged screen content before bed.
• Exercise regularly, but avoid intense late sessions when they interfere with falling asleep.
• Keep the bedroom cool, dark and quiet, and reserve it mainly for sleep rather than work.
• Use a calm wind-down routine and avoid lying awake to force sleep; get up briefly if rested.
• If considering melatonin, ask a pharmacist or GP about timing, dose, interactions and product quality.

If melatonin is used, it should be treated as timed support. A low dose may be enough for a timing problem, while higher doses do not automatically improve sleep and can increase morning grogginess, headache, dizziness or vivid dreams. People taking medicines for sedation, blood clotting, blood pressure, diabetes or seizures should check with a pharmacist or doctor. Melatonin should not be assumed to be suitable during pregnancy, breastfeeding or for children without professional advice. Anyone who feels drowsy after taking it should avoid driving or operating machinery.

Seek medical assessment if poor sleep persists despite good habits, causes significant daytime impairment, or comes with loud snoring, choking, morning headaches or unusual movements during sleep. A general practitioner can review medications, mood, alcohol and other conditions, and refer for specialist sleep assessment when appropriate. Further information from the publisher is available through contact Healthy Life Live, while persistent symptoms should be discussed with a qualified health professional. Persistent sleep problems deserve assessment rather than repeated self-treatment, because the most effective route depends on what is disrupting sleep.