The Use of Melatonin in Children

This week, I was deeply immersed in the “Introduction to Hormonal Modulation” course, isolated from everything else, with around 90 participants, including doctors, some pharmacists, and other healthcare professionals.

One of the lectures focused on Melatonin, whose use in children has been well-established for over 30 years, based on studies in very specific situations. In fact, melatonin has been used in this age group for more than 20 years, but its indications are precise, given the numerous interactions with other hormones.

I was astounded to learn that there are numerous melatonin products on the market for pediatric use! I am aware of patients who were advised by pediatricians to give melatonin to their children.

It seems that many people mistakenly believe that over-the-counter melatonin is harmless, but this is not the case. There are numerous hormonal and drug interactions that should not be overlooked. I will focus on children, as my goal is to raise awareness about this issue, which, apparently, is not well understood by pediatricians or parents, despite its over-the-counter availability.

This issue must be publicly addressed because melatonin is a hormone with significant implications for other hormonal systems. The consequences of its use in children can be severe, including delayed puberty, inhibition of hormones that regulate sex hormones, suppression of ACTH (adrenocorticotropic hormone, which stimulates cortisol production, vital for our health!), and MSH (melanocyte-stimulating hormone, responsible for skin pigmentation).

Melatonin also reduces insulin levels and increases glucose sensitivity, which can disrupt carbohydrate metabolism. Children who have a mutation in the MTNR1B gene (found in 30% of the population) may develop diabetes due to inhibited insulin secretion.

In terms of thyroid function, melatonin enhances the conversion of T4 to T3, meaning that the inactive thyroid hormone secreted by the thyroid gland is converted into the active hormone. This can lead to symptoms of “excess” thyroid hormones, such as night-time palpitations, sweating, and increased heart rate.

Moreover, melatonin exerts an inhibitory effect on the hypothalamic-pituitary axis, reducing levels of TSH (thyroid-stimulating hormone) and T4 (thyroxine, the inactive form), while stimulating the conversion of T4 to T3, the active form, as mentioned earlier.

Prolonged supplementation with melatonin can lead to a blockage of TSH activity in thyroid cells, resulting in decreased thyroid hormone production. Studies have shown that TSH, T3, and T4 levels are lower in individuals supplemented with melatonin.

It is important to note that melatonin also inhibits the effect of anticonvulsant medications (e.g., phenobarbital, carbamazepine, phenytoin, etc.).

A fetus produces melatonin only after birth. It is the mother’s melatonin that regulates the circadian rhythm of the fetus, influencing its health. The child’s sleep pattern is established during the final stages of pregnancy and regulated by maternal melatonin.

Melatonin should never be given simply because the child “sleeps poorly.” Doing so could lead to developmental problems in adolescence, including delays in sexual development, among other issues.

The indications for melatonin use in children are very specific and include:

  • ADHD
  • Autism
  • Blindness
  • Cerebral palsy with intellectual impairment
  • Epileptic headache

To make matters worse, some parents use doses that are higher than those I might recommend for adults, not realizing that when it comes to melatonin, where our bodies produce between 0.01-0.1 mg per day, “less is more.” Excessive doses can lead to issues such as sleeping for 3-5 hours and then waking up unable to fall back asleep, experiencing very “intense” or “vivid” dreams, a heavy-headed feeling upon waking, and prolonged morning drowsiness.

There is an urgent need to educate pediatricians and the general public, as we are witnessing a society that is over-medicated, unhappy, and unproductive. We are increasingly acting too early, exacerbating the current state of society by overmedicating individuals who do not need it, especially children.

As a doctor dedicated to Hormonal Modulation and as a concerned citizen who does not want this world for my children and grandchildren, it is crucial that we do what we can. I appeal to you to bring this issue into the public eye, as it is truly shameful that this is happening. Unfortunately, it seems that INFARMED (National Authority for Medicines and Health Products) allows this to happen, and many doctors know little about hormonal balance, instead overprescribing medications to address symptoms of imbalance, further exacerbating long-term health problems.

Moreover, parents, due to a lack of knowledge and because melatonin is available over-the-counter, are also giving it to their children.

According to recent data, the consumption of melatonin has increased by around 600% in recent years.

The concern now extends beyond the grave misuse of this substance and its long-term consequences for children. We must also consider the excipients and capsules in these supplements, which are ingested by an immature body and can be highly toxic, depending on the brand, and may accumulate over time. People often forget that the liver must “metabolize” everything we ingest. Additionally, melatonin may impair the liver’s elimination pathways, particularly the Cytochrome P450 system, leading to potentially toxic levels of other substances.

In conclusion, we must act. I do not have the power to address this issue on my own, so I implore you to help raise awareness.