Neurology
Melatonin
A sleep-regulating hormone — A hormone used for short-term insomnia and certain sleep problems — gentler than traditional sleeping pills.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
Melatonin is a version of the body's own sleep-signalling hormone, used for short-term insomnia (especially in older adults) and for certain sleep disorders, including in some children under specialist guidance.
How it works
The body naturally releases melatonin in the evening to signal that it is time to sleep, helping set the internal body clock. Taken as a medicine at the right time, it reinforces that signal, helping sleep come more easily and improving its quality.
In practice
In practice melatonin offers an alternative to traditional hypnotics (benzodiazepines and Z-drugs) without their dependence and falls risk, which makes it particularly useful in older adults with insomnia and in specific situations such as sleep problems in children with neurodevelopmental conditions and in some shift-work or jet-lag contexts. It tends to help people fall asleep and improves sleep quality rather than acting as a heavy sedative, and the prolonged-release form is the usual choice for older adults with short-term insomnia. It is generally well tolerated; the practical points are that it can still cause some daytime drowsiness, that it interacts with a few drugs (and alcohol), and that — as with any sleep aid — it works best alongside good sleep habits rather than as a stand-alone fix. Timing relative to the intended bedtime matters for its effect.
Examples
Practical use
How to take it & use it well
- Take melatonin a short time before your planned bedtime, as advised, so it works with your natural sleep timing.
- Swallow modified-release tablets whole with water and do not crush or chew them unless your pharmacist confirms it is suitable.
- Keep your bedtime and wake time as regular as possible, since melatonin works best alongside good sleep habits.
- Use it for the short period recommended rather than indefinitely, and review with your prescriber whether you still need it.
- Avoid alcohol around the time you take it, as this can affect sleep quality and add to drowsiness.
- Do not drive or operate machinery if you feel drowsy the next morning, and tell your prescriber if this happens.
Common uses
- Short-term insomnia (often in adults over 55)
- Sleep problems in some children with neurodevelopmental conditions (specialist)
- Jet lag and some circadian-rhythm problems
Monitoring
- Sleep response and daytime alertness
- Continued need (often intended as short-term)
- Any interacting medicines
Weighing it up
Advantages & disadvantages
Advantages
- Can help with short-term sleep problems, particularly difficulty falling asleep, in suitable people.
- Useful for jet lag and for resetting sleep timing in some situations.
- Generally well tolerated for short-term use with relatively few side effects.
- Works with the body's natural sleep signal rather than acting as a strong sedative.
Disadvantages
- Is mainly intended for short-term use, and long-term use should be reviewed with a prescriber.
- Can cause daytime drowsiness, headache or dizziness in some people.
- Timing matters, as taking it at the wrong time can shift sleep in an unhelpful direction.
- Use in older adults and in children usually needs specialist guidance and careful review.
Key safety principles
What to watch for
- Can cause some daytime drowsiness — take care driving if affected.
- Interacts with a few medicines and with alcohol.
- Best combined with good sleep habits; timing relative to bedtime affects how well it works.
Key interactions
What to avoid or check alongside
- Taking melatonin with other sedating medicines, such as benzodiazepines or strong painkillers, can add to drowsiness.
- Some medicines that affect liver enzymes, including fluvoxamine, can raise melatonin levels and increase its effect.
- Alcohol can both reduce melatonin's benefit and add to drowsiness, so it is best avoided.
- Melatonin may affect blood-clotting control in people taking warfarin, so any unusual bruising or bleeding should be reported.
- Tell your pharmacist about all your medicines, as melatonin is sometimes bought without prescription.
Patient & carer advice
- Take it at the time advised before bed for the best effect
- Combine it with a wind-down routine and good sleep habits
- Avoid alcohol with it and see how it affects you before driving
Answers
Melatonin: frequently asked questions
When should I take melatonin?
It is usually taken a short time before your planned bedtime so it supports your natural sleep signal. Your prescriber or pharmacist will tell you the best timing for your situation.
Is melatonin meant for long-term use?
It is mainly recommended for short-term sleep problems. If you feel you need it for longer, this should be reviewed with your prescriber so the cause of poor sleep can be addressed.
Can children and older adults take melatonin?
Both can in some situations, but this usually needs specialist guidance. Older adults can be more sensitive to drowsiness, and children's use should be supervised by a specialist.
Will melatonin make me drowsy the next day?
Some people feel drowsy, dizzy or have a headache the next morning. If this happens, avoid driving or using machinery until you feel alert and tell your prescriber, as the timing or dose may need review.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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