Melatonin
Melatonin is a hormone that helps regulate the sleep–wake cycle. In the UK, prescription-only prolonged-release melatonin (for example the brand Circadin) is licensed for primary insomnia in people aged 55 and over when a prescriber judges it appropriate.
This medicine is part of the Mental health medicines category.
Generic name: melatonin
Quick answers
Short replies to searches people often run before speaking to a clinician. For the overview of what the medicine is used for, see the short summary under the page title above.
What is it for?
Melatonin is a hormone that helps regulate the sleep–wake cycle.
How long does it take to work?
Onset varies by condition and dose. Your GP or pharmacist can explain what to expect and when to review.
What are common side effects?
Possible effects include headache, daytime sleepiness, dizziness, and gut upset.
Can you take paracetamol or ibuprofen with it?
Ask your GP or pharmacist before taking Melatonin with paracetamol or ibuprofen. Many adults use paracetamol for short periods when appropriate; NSAIDs such as ibuprofen need extra checks with your other medicines and health conditions.
More about what Melatonin is used for
Melatonin is a hormone that helps regulate the sleep–wake cycle. In the UK, prescription-only prolonged-release melatonin (for example the brand Circadin) is licensed for primary insomnia in people aged 55 and over when a prescriber judges it appropriate.
Other melatonin-containing products may be sold for short-term jet lag relief under pharmacy control — rules and strengths differ; always follow the pack and pharmacist advice.
How does Melatonin work, and how long does it take to work?
It mimics natural melatonin, signalling night-time to the body’s clock, which can help some people fall asleep or maintain sleep.
It is not a strong sedative like Zopiclone and does not suit everyone.
How and when should you take Melatonin?
For prescribed prolonged-release tablets, timing is usually 1–2 hours after food, at the same time each evening — follow your specific leaflet.
Jet-lag products have different dosing windows; do not exceed labelled duration or dose.
What are the common side effects of Melatonin?
Possible effects include headache, daytime sleepiness, dizziness, and gut upset. Many people have minimal side effects.
Serious side effects of Melatonin — when to get urgent help
Seek help for severe allergic reaction, chest pain, or mood changes that concern you.
What if you miss a dose of Melatonin?
If you miss a prescribed night dose, skip it and continue the next night unless your prescriber says otherwise. Do not double up.
Who should not take Melatonin?
Autoimmune conditions, liver problems, and pregnancy or breastfeeding need individual advice before use. Not all products are suitable for children — specialist paediatric use only when prescribed.
Tell your doctor if you take Warfarin, cimetidine, quinolone antibiotics, or other sedatives.
Can you take paracetamol or ibuprofen with Melatonin? — other interactions
Fluvoxamine and some other medicines can raise melatonin levels. Caffeine or smoking may reduce effect. Always check combinations with a pharmacist.
Melatonin in pregnancy and breastfeeding
Discuss with your GP or midwife before use.
Blood tests and monitoring on Melatonin
Short courses may need little monitoring; prescribed use may be reviewed for benefit and side effects.
What might your GP prescribe instead of Melatonin?
Sleep hygiene, CBT-I, review of pain, mood, or other medicines affecting sleep, or other hypnotics under medical supervision may be considered.
Reviewed by UK registered pharmacists
Reviewed by UK registered pharmacists for accuracy and clarity. Content is informational only.
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Frequently asked questions about Melatonin
People also ask — common Google searches
- What is Melatonin used for?
- Melatonin is a hormone that helps regulate the sleep–wake cycle. In the UK, prescription-only prolonged-release melatonin (for example the brand Circadin) is licensed for primary insomnia in people aged 55 and over when a prescriber judges it appropriate.
- How long does Melatonin take to work?
- Onset varies by condition and dose. Your GP or pharmacist can explain what to expect and when to review. Always follow your prescriber’s follow-up plan.
- Can you take Melatonin with paracetamol or ibuprofen?
- Ask your GP or pharmacist before taking Melatonin with Paracetamol or Ibuprofen. Many adults use paracetamol for short periods when appropriate; NSAIDs such as ibuprofen need extra checks with your other medicines and health conditions.
- What are the side effects of Melatonin?
- Possible effects include headache, daytime sleepiness, dizziness, and gut upset. Many people have minimal side effects. See the sections below for more detail, including serious side effects and when to seek urgent help.
- Is melatonin available on the NHS?
- Prescription melatonin is used in some cases, often for defined groups or formulations. Availability depends on local guidance and your prescriber’s assessment.
- Can I buy melatonin online?
- Only use reputable UK pharmacy sources and follow legal supply rules. Strengths and licences differ from other countries; your pharmacist can advise.
Need personalised advice?
Your local pharmacist or GP surgery can help with questions about your medicines, side effects, and alternatives that may be suitable for you.
Links open the NHS website for finding services. DrugABC does not sell prescription-only medicines or replace clinical care.
Often used with
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