Melatonin

Sounds like 'mel-a-to-nin'

Melatonin is used to treat sleep problems. Find out how to take it safely and possible side effects.

On this page you can find information about:

Type of medicine Also called
  • Medicine to improve sleep
  • Circadin®
  • Vigisom®
  • Country Life®

What is melatonin?

Melatonin is a hormone made by the pineal gland in your brain. It helps to control your body's sleep pattern and sleep–wake cycle. The level of melatonin in your body increases soon after the onset of darkness and is highest between 2–3 am. Melatonin production is suppressed by light. It seems that less melatonin is produced as you get older. 

What is melatonin used for?

Melatonin, as a supplement, is available as tablets and capsules. Below are some common uses of melatonin.

Sleep problems (insomnia)
Melatonin can help shorten the time it takes you to get to sleep by about 10 minutes. It can also help the quality of your sleep. It is best to use melatonin for a short time only, to help you get back into a good sleep habit. Read more about sleep problems (insomnia) and tips to improve your sleeping habits.

Neurodevelopment disorders with sleep problems in children
Melatonin may be prescribed for children and young people up to the age of 18 years who have neurodevelopment disorders that make it difficult to sleep.

Jet lag
There is some evidence that melatonin can be effective for the prevention of jet lag (when taken at the right time). Melatonin is not registered for this use in Aotearoa New Zealand. Take to your doctor for more information.

Where can I get melatonin from?

In Aotearoa New Zealand, melatonin is mostly available as:

  • Tablets or capsules (1 mg, 2 mg, 3 mg). When you take these, the melatonin is released straight away.
  • Modified release tablets (2 mg, 3 mg). Modified release (also called slow release) means that the medicine is released slowly over several hours.

To ensure the safe use of melatonin supplements, you can only get melatonin through a prescription from your doctor or after a consultation with a pharmacist. 

 Availability of melatonin in Aotearoa New Zealand
Prescription from your doctor If your doctor has prescribed you melatonin and you meet certain criteria (such as being diagnosed with persistent and distressing insomnia because of a neurodevelopmental disorder and are under the age of 18 years), you may be eligible to have melatonin funded. Check with your healthcare team.
Consultation with your pharmacist If you are using melatonin for sleep problems, you can buy it from some pharmacies after a consultation with the pharmacist. You need to be aged 55 years or over to be eligible for this service and no more than 13 weeks can be given. Only pharmacists who have completed additional training can supply melatonin. To make sure it is safe for you, they will ask you questions about things like other medicines you are taking. The pharmacy will also need to record your name and address.
Buying melatonin from abroad Melatonin purchased outside of a pharmacy in Aotearoa New Zealand is not guaranteed in terms of its quality or safety. All incoming medicines must be declared by NZ customs.

Precautions before taking melatonin

  • Do you have an autoimmune disease (a condition in which your body is attacked by its own overactive immune system) such as rheumatoid arthritis, multiple sclerosis or lupus?
  • Do you have problems with the way your kidney or liver works?
  • Do you have epilepsy, high blood pressure or diabetes?
  • Do you have depression?
  • Are you pregnant or planning a pregnancy?
  • Are you breastfeeding?

If you answered yes to any of these questions, it’s important that you tell your doctor before you start melatonin. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

How to take melatonin

  • Timing for sleep problems:
    • Take your melatonin dose right before bedtime or, for slow release tablets, take 1 or 2 hours before bedtime.
    • Take with or after a meal or snack. 
    • It is important to take your dose at the correct time. If taken at the wrong time of the day it is likely to cause daytime sleepiness, particularly if combined with other medicines.
  • Swallow slow-release tablets whole: Do not crush, chew or divide them because this will release all the medication at once. The slow-release tablets have been designed to release the right dose of medicine while you sleep. If you crush, chew or divide the tablet the melatonin can be released straight away so it will work quickly.
  • Effects of melatonin may not be immediate: The effects of melatonin may not be immediate and it may take a few days for you to experience the full benefits. It's important to take your dose regularly.
  • Missed dose: It is not harmful if you miss your melatonin dose. If you forget to take your dose at the usual time, but you remember before you go to sleep, take it when you remember. But if you do not remember until the following day, just take the next dose at the right time. Do not take double the dose.
  • Do not take melatonin for longer than your doctor advises: Melatonin does not work for everyone, so see your doctor if you have finished your treatment course but keep having sleep problems.

Cautions while taking melatonin

  • Alcohol: Limit or avoid alcohol while taking melatonin because alcohol can affect how it works.
  • Caffeine: Avoid products with caffeine in them as caffeine can affect how melatonin works.
  • Smoking: Tobacco smoking affects melatonin levels. If you smoke, your doctor can advise you on what dose of melatonin is best for you.
  • Effects on driving: Avoid driving after taking melatonin.
  • Interaction with other medicines: Melatonin can interact with other medicines, herbal supplements and rongoā Māori so check with your doctor or pharmacist before starting melatonin or before starting any new products. This is especially important if you are taking other medicines that can cause drowsiness or if you are taking warfarin (as it may alter the INR).

Possible side effects

Like all medicines, melatonin can cause side effects, although not everyone gets them. Often side effects improve as your body adjusts to the new medicine.

Side effects What should I do?
  • Feeling tired or sleepy
  • Drowsiness
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Indigestion
  • Stomach upset
  • Nausea (feeling sick)
  • Dry mouth
  • Try taking melatonin with food or a snack.
  • Muscle, bone or joint pains 
  • Feeling restless
  • Anxiety
  • Irritable
  • Strange dreams
  • Tell your doctor if these side effects bother you.
For more information on side effects, see the Medsafe consumer information leaflets below.

Did you know that you can report a medicine side effect to the Centre for Adverse Reactions Monitoring (CARM)? Report a side effect to a product.

Learn more

The following links have more information about melatonin. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Circadin  Medsafe Consumer Information, NZ
Vigisom Medsafe Consumer Information, NZ
Melatonin Sleep Health Foundation, AUS
Melatonin – your brand is changing Pharmac, NZ
Importing Medicines FAQ Medsafe, NZ

References

  1. Melatonin NZ Formulary, NZ
  2. Melatonin NZ Formulary for children, NZ
  3. Melatonin – is it worth losing any sleep over? BPAC, NZ
  4. Melatonin – don't lose sleep over it SafeRx, NZ
  5. I dream of sleep – managing insomnia in adults BPAC, NZ

Additional resources for healthcare professionals

Credits: Sandra Ponen, Pharmacist. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 16 Feb 2022