Let’s talk: Melatonin

Melatonin has really made it into the spotlight recently for people with insomnia, pregnancy, jetlag and children with ASD or ADHD. But what is melatonin, how does it work and does it improve our sleep?

What is melatonin?

Melatonin is a hormone made in the body in response to darkness, to help with the timing of the circadian rhythm and sleep. It is made in the pineal gland in the brain but also in the eyes, bone marrow and gut. Ideally, tryptophan and serotonin keep us awake during the day and as the sun starts to set, the tryptophan is converted to melatonin using the serotonin to help us sleep at night. Once we are asleep, the melatonin in our body slowly decreases so that we can stay awake during the day. It’s a pretty cleaver system! 

Although melatonin is responsible for helping us get to sleep, it doesn’t impact the quality of our sleep or how long we sleep for. There are other hormones that impact these factors.

Along with helping us get to sleep, melatonin has many other functions in the body including involvement in:

Melatonin has also been linked to many gastrointestinal conditions including IBS, IBD, and colon cancer, and some psychiatric disorders and cardiovascular diseases.

As as supplement, melatonin can help reset the internal body clock. Melatonin supplements can be made from animal or microorganisms but most are synthetic.

Side effects of melatonin

Side effects of taking melatonin can include:

Due to the effect of melatonin on the digestive system, constipation and diarrhea can also be experienced when taking melatonin.  Melatonin does not cause weight gain, in fact it can assist with weight loss.

Are melatonin gummies safe for children?

Many children have trouble sleeping which causes stress for the entire family. A study from Central Queensland University found among 255 parents in Australia, 70% used melatonin for their children! So is it safe? 

For children who have a diagnosis of ASD (autism spectrum disorder) or Smith Magenis Syndrome, the Therapeutic Goods Administration (TGA) in Australia recommends the prescription of melatonin by a health professional only, and only when sleep hygiene measures have been insufficient. The TGA does not recommend melatonin for children outside of these circumstances as often childhood sleep problems can be managed with behavioural and psychological sleep techniques. It is also not recommended for children to take melatonin every night as your child’s body gets used to it and they require higher doses as time goes on, which increases the risk of adverse effects.

The difficulty in analysing if melatonin gummies are safe for children is that many of them are bought online and the quality and integrity of the labelling is questionable. In one study of 31 melatonin supplements, 26% had a significnat inconsistency between the amount of melatonin on the label and the amount in the supplement.

A 2022 report from the US Centers for Disease Control and Prevention found from 2012 to 2021, there was a 530% increase in paediatric ingestions of melatonin reported to poison control centres. Although most of these were asymptomatic, those with symptoms included gastrointestinal, cardiovascular and central nervous system problems. Of the most serious, five children required mechanical ventilation and two died. So melatonin supplementation needs to be taken seriously.

At the end of the day, we lack research on the optimal dosages, timing and the long term effect of using melatonin supplements with children, so we can’t determine if they are safe or not.

Use of melatonin in pregnancy and breastfeeding

Many people experience insomnia during pregnancy and with sleep disruption in the postpartum period, many reach for melatonin.   Melatonin has also been used an antioxidant treatment for conditions during pregnancy such as hyperglycemia and preeclampsia, so the research suggests melatonin use during pregnancy and breastfeeding is probably safe in humans. However, we are lacking research in this area as there is conflicting evidence when we look at animal studies. For example, a study that look at the use of melatonin during pregnancy in sheep found potential adverse effects, including decreased birth weight and prolonged gestation. As melatonin does cross the placenta, it is important to follow medical advice if you are using melatonin during your pregnancy. 

Infants don’t produce melatonin until about 3 months of age so until then, they are relying on you! The melatonin in breastmilk follows a circadian rhythm where there is more melatonin in breastmilk that is produced in the evening compared to breastmilk that is produced in the morning. A systematic review conducted in 2022 found no clinical trials investigating safety or efficacy as an outcome of supplemented melatonin use during breastfeeding, revealing a significant gap in the literature. However as infants take longer to clear medications and supplements from their system, caution is advised.

Can melatonin help those with ASD and/or ADHD?

The current research suggests melatonin can be helpful for those with ASD and ADHD. However, it is important to also address any other factors that could be impacting sleep before reaching for melatonin. This includes:

When is melatonin useful?

A melatonin supplement can be helpful for those experiencing jet lag, delayed sleep-wake phase disorder (which is different to insomnia), and for those experiencing anxiety before surgery.  If you don’t fall into these categories, it is recommended to find out why you’re not sleeping and address that issue. 

How else can I improve my sleep?

There are a number of ways to improve the duration and quality of your sleep, including: 

If you’re interested in taking any supplements, please discuss this with your practitioner to ensure you’re taking the correct dose and form for you. This article is not intended to be medical advice and is purely for education purposes.