8 questions about melatonin that you did not know who to ask

Melatonin. Have you already said thanks for it?

Thanks to melatonin you sleep when it is dark and you can get a wide variety of benefits that only happen thanks to a good night’s sleep, ranging from muscle and emotional restoration to memory fixation.

You surely have heard a lot about melatonin. It is impossible to open a post or article about sleep and not find out about the ‘sleep hormone.’

If you still have doubts about it, it is time to find answers.

1. What is melatonin?

Melatonin is a natural hormone secreted by the pineal gland, a small endocrine gland located in the brain of vertebrates.

Popularly known as the ‘sleep hormone’, the production of melatonin is triggered by darkness. That is why we naturally feel sleepy at night and wake up in the morning, when light interrupts the activity of the pineal gland.

This process explains why this hormone essential in regulating the circadian rhythm and, consequently, in the sleep cycle.

Melatonin can also be produced synthetically in laboratories. More on that below.

2. Is melatonin sale forbidden in Brazil?

Not anymore. In 2017, the justice allowed the importation of melatonin as a pharmaceutical supply in Brazil. Since then, it can be sold in compounding pharmacies under medical prescription.

In 2021, ANVISA also freed the use of melatonin for formulating food supplements. According to the entity, these supplements must be destined exclusively for people aged 19 and older, and its maximum daily dose is 0.21 mg.

Despite the surprise and dissent on releasing melatonin as a ‘food supplement,’ exogenous melatonin can already be purchased throughout Brazil without medical prescription.

3. Is melatonin harmful?

Despite being produced by the body, an exaggerated consumption of exogenous melatonin (the kind produced in laboratories) can be harmful.

In excessive doses, the hormone may have the opposite effect as desired because of an important disruption of the circadian rhythm, which becomes ‘confused.’ The result is notable daytime drowsiness, lack of sleep at night and the presence of nightmares and/or vivid dreams.

Other effects of overconsumption are nausea, dizziness, irritability, anxiety, bowel disorders and joint pains, among others. And yes, in theory, you can have a melatonin overdose.

Do not use melatonin or any other drug without medical prescription.

4. Can melatonin lead to addiction?

Technically, melatonin does not lead to addiction, since there are no studies proving the presence of addictive proprieties. This does not mean that it is harmless.

An excessive intake of the exogenous hormone can make its natural production drop, creating dependence, which is different from addiction. See also item 3 in this post.

5. What is the ideal dose of melatonin?

The medical community has no consensus on the ideal dose for the general population. The quantity for each patient must be determined individually by the treating doctor.

 If you are taking melatonin and still have difficulties sleeping or are feeling drowsy during the day, contact your doctor. It may be a signal of a too low or too high dose.

6. Can children take melatonin?

The Boston Children’s Hospital explains that, ‘in general, melatonin seems to have relatively few side effects in children, most of them minor, such as increased bedwetting, nightmares, and morning grogginess.’

However, the Hospital also explains that the hormone can only be administered in children aged three and older and after medical research to identify if the difficulties in sleeping are situational or if they appear due to other sleep disturbances, such as apnea or restless leg syndrome.

For children with Autistic Spectrum Disorders, the use of this hormone can be especially beneficial.

Yet again, we recommend never taking or giving your child any drug or supplement without medical prescription.

7. Besides regulating sleep, what else does melatonin do?

Besides regulating the circadian rhythm, melatonin acts in different body parts.

According with IIMEL – Instituto Internacional de la Melatonina, linked to the University of Granada, Spain, extra-pineal melatonin (the kind produced outside of the pineal gland) has anti-inflammatory and anti-oxidative properties, working as a cytoprotector to maintain cell health.

8. Is it true that melatonin prevents Coronavirus?

Melatonin does not prevent a person from testing positive for sars-cov-2, or Covid-19, but it acts as a kind of barrier that prevents pulmonary cells from being infected by the virus and, consequently, activates the immunological system. The virus keeps circulating in the respiratory tract for some days and, with time, it disappears without causing the disease (asymptomatic).

However, Regina Pekelmann Markus, a teacher at the Instituto de Biociências at USP who led the study that came to these findings, highlights two important alerts. First, the infected person, even when asymptomatic, keeps breathing out polluted air that may infect those around him/her. It is essential that everybody keeps using facemasks and maintain social distance.

Additionally, the hormones in this study ‘have nothing to do with melatonin for sleep, that people can take,’ but with melatonin produced in the lungs.

Nasal administration of melatonin, either in drops or spray, was considered in the research, but not studied yet. Thus, there is no study that let us say that taking melatonin helps prevent Coronavirus. Don’t go running to the store.

If you have any doubt about melatonin, ask us on Persono’s Instagram for us to answer there and update this post for everyone to read.