Melatonin: How Your Body's Sleep Hormone Works
Melatonin: How Your Body's Sleep Hormone Works
It's almost 1am, you've got an early call tomorrow, and you're still staring at the ceiling after a long day of back-to-back meetings and a heavy plate of char kway teow for dinner. Someone mentions melatonin gummies. But what is this hormone actually doing inside your body, and why does it work for some sleepless nights and not others?
What Is Melatonin?
Melatonin is a hormone your own body makes — you don't need to eat or take anything for your body to produce it.
It comes from a tiny gland deep in the brain, and its main job is to help regulate your sleep-wake cycle by working with your body's internal clock and your eyes' response to light.
Levels naturally climb once it gets dark and drop again as the sun comes up, which is why melatonin is often nicknamed the body's own "lights out" signal.
Melatonin supplements sold in pharmacies and health stores are usually made synthetically in a lab, though some are derived from animals or microorganisms. Manufacturing isn't tightly standardised everywhere, and studies checking over-the-counter melatonin products have found that the actual amount inside a bottle can vary a lot from what's printed on the label.
Why Do People Take It?
Easing Jet Lag
This is probably melatonin's best-known use, and it matters for a region full of frequent flyers between Singapore, Kuala Lumpur, Manila, and beyond. Jet lag happens when your internal clock is still set to your departure city while your surroundings have moved on to a completely different time zone, leaving you tired, foggy, and off your usual eating and sleeping rhythm. Research reviewed by health authorities suggests melatonin supplements can help reduce overall jet lag symptoms compared with a placebo, particularly after long eastward flights. Timing matters here — taken at the wrong point in the day, melatonin can actually push your adjustment in the wrong direction instead of helping it.
Resetting Shift Work Sleep Patterns
Rotating or night shifts are common across healthcare, aviation, logistics, and manufacturing roles in Singapore and Malaysia, and they wreak havoc on the body's natural rhythm. Sleep medicine guidelines recommend melatonin to help night shift workers fall asleep during the day when their bodies would normally expect to be awake. It's used the same way for people trying to sleep and function well after their shift schedule flips their usual routine upside down.
Delayed Sleep-Wake Phase Disorder
Some people, especially teens and young adults, have body clocks that are naturally shifted later — they simply can't fall asleep before the early hours of the morning and struggle to wake up for a 9am start. This is a recognised condition called delayed sleep-wake phase disorder. Clinical guidelines note that taking melatonin at a specific time before the desired bedtime, combined with a consistent wake-up routine, can help shift sleep onset earlier and improve how well someone functions the next day, though the benefit tends to be modest.
Occasional Sleeplessness
For everyday insomnia — the kind brought on by a stressful PMEB workload, screen time right before bed, or a stimulant-heavy diet of teh tarik and kopi — melatonin's effect is generally mild. Evidence suggests it may slightly shorten the time it takes to fall asleep, but it doesn't reliably improve total sleep time or sleep quality for everyone. It may be more noticeable in older adults, whose natural melatonin production tends to be lower to begin with.
Bioavailability & Absorption
Your body's own melatonin production naturally declines as you get older, which is one reason sleep can become lighter and more fragmented with age. Supplemental melatonin is typically taken orally as a tablet, capsule, gummy, or liquid, and how well it's absorbed and how long its effects last can vary depending on the formulation — immediate-release versions act faster, while extended-release versions are designed to mimic the body's natural overnight pattern more closely.
A few everyday habits can influence how your own melatonin behaves, even without a supplement. Smoking, for instance, has been shown to reduce how much melatonin stays active in the body. Because manufacturing of melatonin supplements isn't consistently regulated across markets, the actual dose inside a product can differ meaningfully from what's stated on the packaging — another reason to buy from a reputable pharmacy rather than an unverified online seller, and to check that any product you're considering is properly registered for sale in Singapore or Malaysia.
Safety Basics
Melatonin is generally considered safe for short-term use in most healthy adults, and unlike many prescription sleep medicines, it isn't associated with dependence or a fading effect over time with continued use. That said, it isn't completely without downsides. Commonly reported side effects include daytime drowsiness, headache, dizziness, and mild nausea. Less common effects can include vivid dreams or nightmares, short-lived low mood, irritability, stomach cramps, and changes in appetite.
Because melatonin can make you drowsy, it's best to avoid driving or operating machinery for several hours after taking it. People with autoimmune conditions are generally advised to be cautious, and anyone on blood thinners, diabetes medication, contraceptive drugs, immunosuppressants, or medicines that lower the seizure threshold should speak with a doctor or pharmacist first, since melatonin can interact with all of these. It's also not well studied in pregnancy or breastfeeding, so it's best avoided unless a doctor specifically advises otherwise.
In Singapore, the prescription-strength prolonged-release brand is only available through a doctor, while other over-the-counter melatonin products are sold more freely — but "available without a prescription" doesn't mean risk-free, especially when combined with alcohol, other sedating supplements, or existing medical conditions. If you're using any complementary health product regularly, it's worth mentioning it to your GP the same way you would any other medication.
Natural Food Sources
Most people don't think of melatonin as something you eat, but small, naturally occurring amounts do show up in a handful of everyday foods. None of these will replace a supplement if you need a therapeutic effect, but they're a reasonable part of a sleep-friendly diet:
- Tart cherries and tart cherry juice — among the most studied natural sources, and often paired with their tryptophan content for a sleep-supporting effect
- Eggs and fatty fish, which are considered some of the better animal-based sources
- Nuts such as pistachios, walnuts, and almonds — a practical grab-and-go snack option
- Legumes including lentils, soybeans, and chickpeas, both familiar in many local vegetarian and plant-based dishes
- Goji berries, often added to soups or eaten dried as a snack
Related Articles
Explore Related Nutrients
Final Thoughts
Melatonin isn't a cure-all for bad sleep, and it won't undo the effects of a genuinely overloaded schedule, late-night screen scrolling, or one too many cups of kopi in the afternoon. Where it does seem to help — jet lag, shift work adjustment, and certain circadian rhythm issues — the evidence is reasonably solid. For everyday tiredness from a demanding, kiasu-paced lifestyle, good sleep habits will usually do more heavy lifting than any supplement.
If you're considering melatonin regularly rather than occasionally, it's worth a conversation with your doctor, especially if you're on other medications or managing an existing health condition. A good night's sleep matters too much to leave to guesswork.
This article is for general informational purposes and is not a substitute for professional medical advice. Please consult a qualified healthcare professional before making any changes to your diet or supplement routine.
References
- NIH NCCIH
https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know - Mayo Clinic
https://www.mayoclinic.org/drugs-supplements-melatonin/art-20363071 - MedlinePlus
https://medlineplus.gov/ency/patientinstructions/000719.htm - PubMed Central
https://pmc.ncbi.nlm.nih.gov/articles/PMC10053496/ - HealthHub Singapore 🇸🇬 SG
https://www.healthhub.sg/medication-devices-and-treatment/medications/melatonin