The human brain is an organ of such complexity that inside it there are thousands of chemicals interacting so that we can experience things and perceive reality as we do.

Our behavior has biological bases that influence us decisively, and among these biological factors that make us as we are are substances like serotonin . Let’s see what makes this hormone so special, and how it influences our brain.

Serotonin: what effects does this hormone have on your body and mind?

Some of these substances can only be found in certain types of cells and have very specific functions (so much so that many of them have yet to be discovered), but others act both in the brain and outside it. This is the case, for example, with serotonin, also known as 5-HT .

5-HT is deeply integrated into the functioning of the human body and learning all its functions by heart can be very intricate. However, in this summary you can learn about six of the main effects that serotonin has on the human body .

1. Has a fundamental role in digestion

Serotonin is a substance that behaves like a hormone in the blood and acts as a neurotransmitter in the brain. That is, serotonin is one of the units of communication that neurons pick up and emit to influence each other, creating brain activation dynamics and chain effects. Thus, serotonin promotes the crossing of information between neurons and, beyond the brain, serves very different purposes. In fact, the highest concentrations of serotonin are not in the brain but in the gastrointestinal tract .

It is in the intestines that one of the most important functions of serotonin becomes important: the regulation of digestion. Too high levels of serotonin are linked to the development of diarrhoea, while an excessive deficit of this substance can lead to constipation. Furthermore, also influences the appearance (or absence) of appetite .

2. Regulates positive and negative moods

Serotonin can be found in large quantities in many parts of the body, and therefore a general imbalance in the production of this substance can have drastic effects on various factors that affect the way we feel and behave .

In particular, serotonin has been associated for many years with symptoms of depression, since people with a disorder of this type usually have low concentrations of 5-HT in their blood. However, it’s not known to what extent it’s a lack of serotonin that causes depression or vice versa.

3.Controls body temperature level

Among the basic maintenance functions of the integrity of our body that we associate with serotonin is also the thermal regulation . This is a very delicate balance, because a difference of a few degrees in body temperature can lead to the massive death of large groups of cellular tissues.

Neurons, for example, are particularly sensitive in this regard.

4.Influences sexual desire

A correlation has been found between serotonin levels and sexual libido. High levels of 5-HT are associated with a lack of sexual desire, while low levels would promote the emergence of behaviors oriented to the satisfaction of this need.

In addition, serotonin also seems to have an effect on the ability of humans to fall in love and feel love for another person. You can find out in this article:

  • “The chemistry of love: a very powerful drug”

5.Reduce aggressiveness levels

Serotonin also serves to stabilize the emotional state of the human being in stressful situations. Specifically, it serves to inhibit aggression and violent behaviour that may result from it. Thus, more impulsive and violent people tend to have lower levels of serotonin acting on key points in the brain than those who are more peaceful.

In addition, this substance is particularly badly tolerated by testosterone , a hormone that, by acting on neurons and making them more insensitive to serotonin, encourages aggressive behaviour.

6.Regulates the sleep cycle

Throughout the day, serotonin levels rise and fall describing the curves that the circadian rhythm marks, which is the schedule our body follows to know when it is time to sleep and when it is not, and therefore regulates our sleep and our wakefulness. Thus, 5-HT levels tend to peak at the sunniest times of the day, while during deep sleep they drop to their minimum.

In this way, the production of serotonin has an influence on regulating our ability to sleep, making it easier or harder to reconcile sleep. Something similar occurs with another substance called melatonin.

Discovering Excess Serotonin Syndrome

Serotonin is found in all healthy human beings, but too much can trigger problems. What happens when our body generates too much serotonin ? This is not a trivial question, as there is a pathology associated with this excess of serotonin.

The excessive consumption of drugs for depression (so-called “antidepressants”), which basically stimulate the production of the hormone serotonin, can have a negative effect on our body. You can discover this by reading this article, where we explain exactly what this syndrome consists of and what symptoms it presents:

  • “Serotonergic syndrome: causes, symptoms and treatment”

Bibliographic references:

  • Afifi, A.K. and Bergman, R.A. (1999) Functional Neuroanatomy. McGraw Hill.
  • Martin, J.H. (1997). Neuroanatomy. Text and Atlas. Madrid: Prentice Hall.
  • Paxinos, G. and Mai, J. (2004). The human nervous system. Academic Press, Inc.
  • Valverde, F. (2002). Structure of the cerebral cortex. Intrinsic organization and comparative analysis of the neocortex. Journal of Neurology. 34 (8).