Melatonin: production in babies (term + preterm) and supplementation

The diurnal rhythm of melatonin production is almost entirely controlled by the body clock. Your body's natural melatonin levels don't make your baby sleep, and don't control your baby's body clock! The melatonin produced naturally by the human body is a follower, not an instigator, when it comes to sleep: your melatonin levels track your body clock settings. The body clock itself is predominantly controlled by the sun and our environment's cycles of light and dark.

When does your baby make her own melatonin?

You can find out what melatonin is, and how it relates to sleep in humans, here. The following can be useful to know about melatonin and babies.

• From about 18 weeks gestation, your baby has melatonin receptors in his body clock and other tissues. Your baby has a low but detectable level of melatonin at birth, which comes through your placenta from your bloodstream, and which lingers in his blood for about a week.

• Baby's pineal gland only starts to synthesise and secrete melatonin after the birth. These levels are undetectable, once the placental melatonin disappears, until about six weeks of age.

• Baby's melatonin levels (whether baby is breastfeeding or not) are still low at three or four months of age. It's only from six months of age that melatonin is a stable part of baby sleep-wake cycles, and by 12 months melatonin levels have increased to 50% of adult values.

Will melatonin supplements help your baby sleep?

If you're desperately sleep deprived, and family and work life seem to be falling apart, you will of course start to think through the options that are available. This might include the flavoured melatonin gummies for infants that you've noticed in your local pharmacy. Melatonin supplements have become very popular for both children and adults in recent years. They are often described as 'safe', 'natural', and as promoting peaceful sleep in young children, but this marketing is misleading.

Melatonin is not recommended for any baby with sleep problems (unless used in the hospital setting, for example, with prematurely born babies). If your baby is otherwise well without serious medical conditions, there is no role for melatonin supplements, because

• They haven't been shown to be effective

• Dosages are still being determined

• They could make your baby's sleep problems worse over time (by not dealing with the real cause)

• May result in a range of side effects, including nausea and vomiting, headaches, fatigue, confusion, nightmares

• Product content is not regulated and may contain unexpected substances

• Melatonin dosages affect individuals differently.

The most empowering steps you can take to enjoy healthy sleep and to keep family body clocks in sync, including when families are living with neurodiverse children, are contained in The Possums Sleep Program.

Why are some preterm babies given melatonin?

The melatonin produced by the human body is

• An antioxidant and scavenger of free radicals

• Anti-inflammatory

• Immunomodulatory.

A low melatonin concentration in preterm infants is a predictor of adverse neonatal outcomes. This can be framed as yet another reason to give premmies their mother's or a donor's breast milk, if at all possible, since breastmilk contains melatonin.

Melatonin supplementation is often given to preterm infants these days, in the hope it might help protect against the possible developmental effects of prematurity. Researchers note that although melotonin supplementation appears to be neuroprotective for preterm infants, with minimal side-effects, and looks to be a promising intervention, safety, efficacy and dosing information in neonates and infants is still lacking.

Why is melatonin given to some babies after surgery?

Melatonin supplementation is also being used in infants after surgery, in the hope it may help protect against postoperative oxidative stress.

Recommended resources

Will dim lights in the evening increase melatonin and make sleep easier for your baby?

Will dim lights in the evening increase melatonin and make sleep easier for your toddler?

Melatonin and human sleep

Can giving baby your expressed breast milk be 'mistimed' because of melatonin levels?

Melatonin research doesn't support the belief that dimming the lights helps with infant sleep

Selected references

Bradford C, Miller J, Harkin M, Chaaban H, Neely S, Johnson P. Melatonin use in infants admitted to intensive care units. Journal of Pediatric Pharmacology and Therapeutics. 2023;28(7):635-642.

Egeli TU, Tufekci KU, Ural C. A new perspective on the pathogenesis of infantile colic: is infantile colic a biorhythm disorder? Journal of Pediatric Gastroenterology and Nutrition. 2023;77(2):171-177.

Garofil F, Franco V, Accorsi P. Fate of melatonin orally administered in preterm newborns: antioxidant performance and basis for neuroprotection. Journal of Pineal Research. 2024;76:e12932.

Givler D, Givler A, Luther PM. Chronic administration of melatonin: physiological and clinical considerations. Neurology International. 2023;15:518-533.

Hausler S, Robertson N, Golhen K. Melatonin as a therapy for preterm brain injury: what is the evidence? Antioxidants. 2023;12:1630.

Owens J, Barnett N, Lucchini M, Berger SE. Melatonin use in infants and toddlers. Sleep Medicine. 2024;120:53-55.

Tordjman S, Chokron S, Delorme R. Malatonin: pharmacology, functions and therapeutic benefits. Current Neuropharmacology. 2017;15(434-443).