Using melatonin for sleep: everything you need to know

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

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 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:  

• Have delayed sleep phase disorder (it reduces the time it takes to fall asleep). 

• Experience insomnia. 

• Want to overcome jet lag. 

• Have too little naturally occurring melatonin (such as those with Alzheimer's disease, severe pain, type 2 diabetes and some mood disorders). 

• Need to reset their body clock for an earlier start at work (shift workers).  

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, 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) 

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 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. The Therapeutic Goods Administration (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 or less. It typically stays in your system for four to five hours, though a safe dose may depend on 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, 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.   

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 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.   

Evidence suggests that melatonin supplements are safe for short-term use. 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 hub.health.

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.