The Woolcock Institute of Medical Research

Despite the widespread use of melatonin as a sleep aid to help with conditions such as insomnia, a Sydney sleep expert says more research is needed to determine the right dosage for the right age group. 

The Woolcock Institute of Medical Research’s leading sleep researcher, Professor Ron Grunstein, says the data currently underpinning melatonin use is based on questionable science and needs further investigation.  

“The efficacy of melatonin is pretty poor. Probably the best evidence we have is in people trying to sleep during the day -- taking it in the evening is not particularly helpful for most people,” Prof Grunstein says.  

 With a recent paper reporting that paediatric overdoses have increased by 530 percent over the past decade in America alone, Prof Grunstein says that until we have more concrete data and a better understanding of the efficacy of melatonin in children, younger people and pregnant women, melatonin should remain prescription-only. 

“It should have never been made over the counter. Melatonin may not be the appropriate treatment for insomnia or other sleep disorders, but people are just being given it.” Prof Grunstein also adds that melatonin has been shown to increase blood glucose levels and worsens diabetes, something that needs to be considered when prescribing and taking melatonin.  

 A recent Woolcock study, published in January 2023, found that while melatonin is relatively safe to use, it should nonetheless be considered a medication that is prescribed by clinicians rather than used as a dietary supplement, as it is in the United States.  

Currently, Woolcock researchers are carrying out an important melatonin trial, the Melatonin for Delayed Sleep Phase Disorder Study. In this study (overseen by Prof Grunstein) researchers are hoping to find out whether a melatonin-like drug, tasimelteon, can help people suffering from Delayed Sleep Phase Disorder (DSPD), a circadian rhythm disorder, defined as a sleep schedule occurring substantially later than the conventional or desired time.  

With 10 to 16% of individuals who suffer from DSPD misclassified with insomnia, Woolcock experts are worried they are being treated inappropriately, and hope the Melatonin for Delayed Sleep Phase Disorder Study will provide accurate diagnosis methods, optimal treatment timing and a pragmatic treatment approach.

A second study, which was recently led by Woolcock sleep expert Dr Camilla Hoyos, investigated whether melatonin can act as a preventive treatment in delaying the onset of dementia, the second leading cause of death among male Australians – and the first for women. 

 “At this point, much of what we understand about melatonin is guesswork,” Prof Grunstein says. “We hope that our studies shed some light on how melatonin interacts with certain disorders, and how we can best tailor dosages for optimum results.”  

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