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Using melatonin for sleep: everything you need to know

Dr Hamish Black

Could melatonin help you sleep better?

A woman sitting at a glass table. She is rubbing her eyes as if she is tired.
A woman sitting at a glass table. She is rubbing her eyes as if she is tired.

Melatonin is most commonly, opens in a new tab used to ease insomnia or help travellers to recover from jetlag.  Could it help you? Read on to find out more.   

What is melatonin?  

Melatonin is a hormone naturally made in your body that controls your sleep. It is produced by the pineal gland in the brain and plays a vital role in regulating our natural sleep-wake cycle (or “circadian rhythm”). Melatonin levels rise about two hours before bedtime to prepare you for sleep and drop to undetectable levels, opens in a new tab during daylight hours.  

How does melatonin work?  

If you’re having difficulty falling asleep, supplemental melatonin could reinforce your cycle of sleeping and waking by sending a stronger signal to your body that it’s time to start winding down. These supplements are most likely to help people on a short-term basis who:  

What impact does melatonin have on your body?  

Melatonin supplements behave in the same way as the natural hormone, helping you relax and feel sleepy. Some people find they stay drowsy the following day, opens in a new tab, especially if they’ve taken the supplement later than recommended.  Taking too much melatonin as a medicine or supplement may cause: 

  • headaches 

  • hypotension (low blood pressure) 

  • hypertension (high blood pressure) 

  • drowsiness 

  • vomiting 

  • alopecia (a health condition causing hair loss) 

Using melatonin  

Melatonin generally works best when you take it about 1 - 2 hours before bed. You'll likely need to work with your doctor to find what dosage and timing works best for you. Melatonin can be safely used, opens in a new tab for up to six months, and some evidence suggests it can be used safely for up to two years in certain patients. 

However, melatonin may interact with other medications, such as antidepressants, so you should always discuss this with your doctor before starting melatonin or any new medication. It's also not recommended to consume melatonin with alcohol or other sedative substances, opens in a new tab. The Therapeutic Goods Administration, opens in a new tab (TGA) advises melatonin should be avoided if you: 

  • Have poor liver function 

  • Have an autoimmune disease 

  • Are under 18 years old 

  • Are pregnant or breastfeeding. 

How long does melatonin last? 

Melatonin supplements will usually begin to take effect in an hour, opens in a new tab or less. It typically stays in your system for four to five hours, though a safe dose may depend on, opens in a new tab your body weight, age and sensitivity to the supplement.  

What is the right dosage?

How much melatonin do I need?  Melatonin is usually sold as 2mg slow-release tablets, opens in a new tab, taken once daily 1-2 hours before you go to bed, and with food. These are available over the counter as pharmacy-only medication for people over 55. If you’re under 55 you’ll need a prescription, opens in a new tab.   

What side effects could you experience?  

While short-term use of melatonin is generally safe for most adults, some people may experience mild side effects, opens in a new tab like dizziness, headache, nausea, and sleepiness. However, melatonin can interact with other medications, so it's important to check with your GP before starting it.   

Melatonin considerations  

Evidence suggests that melatonin supplements are safe for short-term use, opens in a new tab. However, remember that in Australia, melatonin is classified as a Schedule 4 prescription-only medicine for under 55s which means you would need a prescription from a healthcare professional to purchase it. It shouldn’t become something you rely on. If you’re experiencing issues with sleep, chat with your GP about long-term methods to help improve your sleep. 

Interested in understanding if melatonin is for you? Start an online consultation with, opens in a new tab.

The information in this article is general information and should not be used to diagnose or treat a health problem or disease. Do not use the information found on this page as a substitute for professional health care advice. Any information you find on this page or on external sites which are linked to on this page should be verified with your professional healthcare provider. 

Dr Hamish Black

Dr Hamish Black

Dr Hamish Black

Dr Hamish Black has been a medical practitioner for more than 25 years. In addition to his role as nib group medical advisor, he still spends two days a week practising as a GP. He has spent many years working in emergency departments and in rural Australia, including a stint with the Royal Flying Doctor Service. Hamish also loves karaoke and dancing (though not that well at either, he says!), with Play that Funky Music by Wild Cherry being his karaoke favourite.