Melatonin and Sleep: What It Is and How Timing Matters
Melatonin sits on pharmacy shelves next to vitamins, which makes it feel harmless and simple. It is a real hormone with real effects, and used well it can help in specific situations. Used badly, it mostly makes people groggy. Here is a plain guide.
Key takeaways
- Melatonin is a timing signal, not a strong sedative.
- It is most useful for jet lag and for shifting a very late body clock earlier.
- Quality of supplements varies, so talk to a doctor or pharmacist before using it, especially for children.
What melatonin does
Your brain releases melatonin in the evening when it gets dark, and levels stay elevated through the night. It tells your body clock that night has begun. It does not directly knock you out the way a sedative does, which is why many people take a supplement and feel nothing much.
When it can help
- Jet lag, especially after eastward travel. See jet lag calculator guide.
- Delayed sleep phase, where the body clock runs very late.
- Shift work, sometimes, to help daytime sleep.
For ordinary insomnia the benefit is small and inconsistent.
Dose and timing
More is not better. Studies often use low doses, around 0.5 to 3 mg, and low doses can work as well as higher ones. Timing matters more than strength: to shift your body clock earlier, melatonin is generally taken several hours before your usual bedtime, not at lights-out. A clinician can give advice for your situation.
Quality and labelling
In many countries melatonin is sold as a supplement and is not regulated as tightly as medicine. A 2023 analysis in JAMA of melatonin gummies found that the amount in many products differed widely from the label, and some contained far more than stated. Where possible choose products that are independently tested, or use a medicine your doctor prescribes where that is the local rule.
Side effects and cautions
Common effects include drowsiness, headache and vivid dreams. Check with a doctor or pharmacist if you take other medicines, are pregnant or breastfeeding, have an autoimmune condition, or have a seizure disorder. For children, use melatonin only on medical advice, and look at habits and routine first.
Do not skip the basics
Light timing, regular hours and a calm evening usually do more for sleep than a supplement. If you reach for melatonin most nights, it is worth asking why, and a short chat with your doctor may uncover a cause.
Frequently asked questions
Is melatonin safe to take every night?
Short-term use appears to be low risk for many adults, but long-term effects are less certain, so check with a clinician if you want to use it regularly.
Can I take melatonin for jet lag?
Many people do, and there is evidence it can help, particularly when travelling east. Timing relative to your destination matters; ask a pharmacist for guidance.
References and further reading: Cohen et al., 2023, JAMA (melatonin gummy labelling); American Academy of Sleep Medicine guidance on melatonin and circadian rhythm sleep disorders.