Melatonin for babies? Unbelievable Breastfeeding Facts

By: Dr. Nazeli Gevorgyan - January 11, 2023 - 7 Minute Read

Melatonin for Babies? | The Milky Box

Have you ever considered what’s beyond the ordinary in your breastmilk? Did you know that melatonin, found in breast milk, holds fascinating secrets?

In this article, we will step into the world of parenting as we unravel the mysteries surrounding melatonin for your baby’s well-being and reveal surprising facts about breastfeeding.

The Power of Breast Milk

Breast milk is the best food for babies, providing health benefits and reducing the risk of illnesses and infections. It contributes to cognitive development, including the potential for higher IQ levels, and may lower the chances of obesity, diabetes, and cardiovascular diseases later in life.

Breast milk is also fascinating in its adaptability. It transforms during a single feeding, visually shifting from watery foremilk to creamier hind milk over a pumping session. Beyond this, it adjusts to meet the changing nutritional needs of growing infants, altering fat and protein levels as babies become more active.

Research suggests it also synchronizes with mothers’ circadian rhythms, providing breastfed babies with advantages in neurological development and sleep patterns.

Breast Milk Benefits | The Milky Box

What Hormones are in Breast Milk?

Breast milk is rich in hormones crucial for a baby’s well-being, including prolactin for milk production, oxytocin for milk ejection and bonding, cortisol for stress response, insulin for glucose regulation and for energy production, and thyroid hormones for overall metabolism. Notably, it also contains melatonin, aiding the establishment of the baby’s sleep-wake cycle. 

Helpful Hormones | The Milky Box

How Does Circadian Rhythm Work?

The circadian rhythm is a 24-hour internal biological clock responding to light changes in the brain. It controls sleep regulation and other physiological processes, including body temperature, hormone production, and metabolism. 

The circadian rhythm synchronizes our bodily functions with the natural day-night cycle. Exposure to light, especially natural sunlight, signals the body that it’s daytime, promoting alertness and activity. In contrast, the absence of light triggers the release of the sleep-inducing hormone melatonin, promoting a state of drowsiness and preparing the body for sleep.

While in the womb, the fetus lacks external stimuli, and neonates are born with an immature system. The establishment of circadian rhythms occurs in the first four months, marked by the regulation of core body temperature and the emergence of melatonin around three months. Cortisol production, also crucial for a functioning sleep/wake cycle, can start as early as eight weeks, aiding infants in adapting to day and night differences after rapid physiological changes at birth.

Melatonin: The Circadian Hormone  

Melatonin, a hormone produced by the pineal gland in the brain, regulates the sleep/wake cycle. Its levels tend to rise in the evening, promoting sleep. Found in breastmilk, melatonin also appears to play a significant role in its advantages, influencing infant health in various ways. 

When Do Babies Produce Melatonin?

In the first few months of life, babies develop their melatonin production, which takes about three to six months. Until then, breast milk is the only external source of melatonin for infants, contributing to the building of their natural sleep-wake cycle

Impact of Lactation Stage

Melatonin levels in breast milk vary with the lactation stage. Nighttime-produced breastmilk in early lactation tends to contain higher levels of melatonin. The highest level is in colostrum (the first milk mom produces), then decreases in transitional and mature milk, indicating a potential connection between melatonin production in breast milk and the developmental stages of the nursing infant. 

When is Melatonin Highest in Breast Milk?

Melatonin levels in breast milk are typically highest during the nighttime.

To support consistent melatonin levels, it’s recommended for mothers to sleep in a dark room and nurse in dim light or darkness. Additionally, exposure to blue lights should be minimized as they can inhibit melatonin production.

Some suggest distinguishing milk pumped during the day and night to support the baby’s sleep pattern even when the mother is away.

How to increase Melatonin | The Milky Box

How Does Breast Milk Help a Baby's Circadian Rhythm?

Breastmilk undergoes significant compositional changes during the day, serving as an example of “chrononutrition.” It’s designed by evolution to signal time-of-day information to infants. For instance, daytime milk contains cortisol and specific amino acids to boost alertness and activity. In contrast, nighttime milk is rich in melatonin and tryptophan, promoting sleep and aiding digestion. 

How Does Melatonin Affect Infants?

In addition to influencing circadian rhythms, melatonin acts like a superhero for your baby. It fights off harmful bacteria, helps control inflammation, and even shapes your baby’s gut bacteria. All of this helps your little one grow at a healthy rate, reducing the risk of obesity and other health issues in the long term. Plus, it creates the perfect environment for the development of a healthy cardiovascular system.

Does Melatonin in Breastmilk Help Baby Sleep?

Infants may experience two common nighttime issues during their early months: colic and disrupted sleep. Infantile colic is characterized by excessive crying and irritability, typically worsening in the evening and night. 

It’s often defined by the “rule of three”: crying for more than two hours per day, over 3 days per week, and lasting longer than three weeks in a well-fed, healthy infant. The cause is probably linked to gastrointestinal issues and gassiness. It typically resolves independently between 4 and 6 months with no treatment.

Melatonin, known for its relaxing and sleep-inducing effects on gastrointestinal muscles, might help your baby sleep better at night, establish a routine, and potentially reduce instances of colic. It syncs the baby’s sleep with the mother’s rhythm, resulting in longer sleep for breastfed infants than formula-fed ones.

A study involving 94 mothers of healthy infants aged 2 to 4 months found that exclusive breastfeeding is linked to fewer and less severe crying episodes, suggestive colic, and a tendency for longer nocturnal sleep.

Melatonin Benefits for Premature Infants

Premature infants miss out on the highest melatonin levels found in the final stage of pregnancy and experience a delay in producing their own melatonin.

Unlike full-term milk, preterm milk contains higher melatonin levels in all lactation stages, compensating for the melatonin shortfall resulting from premature birth. This can be beneficial for premature infants in their vulnerable early weeks, potentially offering protective effects for both the brain and the heart, given their higher risk for developing health issues.

Melatonin Benefits | The Milky Box

Stay Curious 

As we conclude our exploration of melatonin for babies and fascinating breastfeeding facts, it’s not just about the science- it’s about the amazing journey of parenthood. Stay curious, stay informed, and enjoy every step of this incredible adventure with “The Milky Box.”


1. Breast Milk’s Circadian Rhythms - La Leche League International (no date). Available at:

2. Engler, A. C. et al. (2012) ‘Breastfeeding may improve nocturnal sleep and reduce infantile colic: Potential role of breast milk melatonin’, European Journal of Pediatrics, 171(4), pp. 729–732. doi: 10.1007/S00431-011-1659-3/METRICS.

3. , M. and Codoñer-Franch, P. (2021) ‘Melatonin in Early Nutrition: Long-Term Effects on Cardiovascular System’, International Journal of Molecular Sciences, 22(13). doi: 10.3390/IJMS22136809.

4. ‘Melatonin’ (2023) Drugs and Lactation Database (LactMed®). Available at:

5. Qin, Y. et al. (2019) ‘Variations in melatonin levels in preterm and term human breast milk during the first month after delivery’, Scientific Reports 2019 9:1, 9(1), pp. 1–5. doi: 10.1038/s41598-019-54530-2.

6. Reddy, S., Reddy, V. and Sharma, S. (2023) ‘Physiology, Circadian Rhythm’, StatPearls. Available at:

7. ‘Breast Feeding and Melatonin: Implications for Improving Perinatal Health’, Journal of Breastfeeding Biology, 1(1), pp. 8–20. doi: 10.14302/ISSN.2644-0105.JBFB-16-1121.

8. Hahn-Holbrook, J. et al. (2019) ‘Human milk as “chrononutrition”: implications for child health and development’, Pediatric Research 2019 85:7, 85(7), pp. 936–942. doi: 10.1038/s41390-019-0368-x.


Please be aware that this information is based on general trends in babies, and it is not medical advice. Your doctor should be your first source of information and advice when considering any changes to your child’s formula and when choosing your child’s formula. Always consult your pediatrician before making any decisions about your child’s diet or if you notice any changes in your child.

Breastfeeding is the best nutrition for your baby because breast milk provides your child with all the essential nutrients they need for growth and development. Please consult your pediatrician if your child requires supplemental feeding.

Nazeli Gevorgyan is a medical doctor from Armenia, and is a researcher in the fields of Obstetrics and Gynecology, among others. Dr. Nazeli is passionate with providing women and parents with reliable and high-quality information on healthy options for infant nutrition, breastfeeding, infant formula, and food. In her free time, she enjoys swimming, traveling, and pottery. 

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Reviewed by Suzanne Renee',

Infant Nutrition Expert

Suzanne Renee' is an accomplished professional with extensive expertise in the area of infant nutrition, dedicated to promoting the health and wellbeing of children. She started this journey as a foster parent.

Suzanne has emerged as a strong proponent of the European baby formula and has become a full-time writer on the subject. 

In her free time, she enjoys camping, hiking, and going to church.