We always hear about hormones and some of the effects they can have on our bodies, but what are hormones themselves? Here we explain it to you.

Hormones are the chemical messengers They control various body functions and circulate through the blood to the tissues and organs. The different types of hormones are released into the blood vessels or interstitial space where they circulate on their own (bioavailable), or are associated with certain proteins until they reach the organs or tissues. Hormones are part of the group of chemical messengers, which also includes neurotransmitters such as dopamine, serotonin or GABA. They affect numerous processes, including:


Metabolism : how the body obtains energy from food

Growth and development

Sexual function

-State of mind


-Monitoring of blood fluid levels



Some of the most important hormones are insulin, thyroid hormones, cortisol, growth hormone and prolactin, among others. Endocrine glands, which are special groups of cells, produce hormones. The main endocrine glands are the pituitary gland, pineal gland, thymus, thyroid, adrenal glands, and pancreas. In addition to the above, men produce hormones in the testicles and women in the ovaries. Hormones are powerful. It takes only a tiny amount to cause major changes in cells or even the entire body. That is why too much or too little of a specific hormone can be serious. Laboratory tests can measure hormone levels with blood, urine, or saliva tests.


Hormones can be natural or synthetic. Natural hormones are secreted by the various glands of the endocrine system. Furthermore, according to their chemical nature, they can be derived from amino acids: peptides or lipids.


Origin – Endocrine system


Pituitary gland


Also called the pituitary gland, it is a small, internally secreting organ located at the base of the brain and connected to the hypothalamus that controls other glands and produces many types of hormones, including growth hormone or GH (a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals), prolactin or PRL (which stimulates the development of mammary acini and the translation of genes for milk proteins), and hormones that stimulate the creation of hormones in other glands such as the thyroid and adrenal glands.




This gland regulates the body’s metabolism, is a protein producer, and regulates the body’s sensitivity to other hormones. It produces the hormone Thyroxine or T 4¸ which regulates metabolic activities and Triiodothyronine or T3, which stimulates the metabolism of carbohydrates and fats, activating the consumption of oxygen, as well as the degradation of proteins inside the cells.




They are four small lentil-shaped glands located in the neck at the back of the thyroid that secrete parathyroid hormone or PTH, which mainly facilitates the absorption of calcium, vitamin D and phosphate.




Glands located above the kidneys whose function is to regulate stress responses. The outer part is called the cortex, which produces steroid hormones such as cortisol, aldosterone, and testosterone.




It is a mixed exocrine and endocrine peritoneal organ. One of the most important hormones it synthesizes is insulin, which is involved in the metabolic utilization of nutrients.


Ovaries and testes


These reproductive organs secrete respective sex hormones that are synthesized from cholesterol. The ovary secretes estrogens and gestagens, and the testicles secrete androgens. Female sex hormones play an essential role in preparing the reproductive system for the reception of sperm and implantation of the fertilized egg. Androgens, on the other hand, are fundamental in the development of the male genital apparatus.


Diseases of the endocrine system


These occur if hormone levels are not balanced or if the body does not respond to hormones as it should. Among the most common are diabetes, a chronic disease caused by insufficient insulin at high blood glucose levels, hyperthyroidism, a situation in which there is an excess of thyroid hormone because it works more than it should, and its opposite case, hypothyroidism, in which it works less than it should.


In the case of chemical messengers of neurotransmitters, we have the following hormones:




It is one of the most famous neurotransmitters of the nervous system, it is also known as the neurotransmitter of pleasure. Its main function is to activate the brain’s reward circuits. Dopamine acts by both activating and inhibiting brain activity depending on where it is released. When we perform actions that our body values as beneficial, dopamine is released. Thus creating a subjective feeling of pleasure that leads us to repeat these behaviors. These behaviors range from the biologically programmed, such as satisfying hunger or thirst, to those that are purely social and learned.




Serotonin is a chemical that helps transmit messages back and forth between nerves in the body. It is a hormone (a neurotransmitter) with a big job to do. Mood, digestion, sleep, and sexuality, to name a few functions, are controlled by serotonin. Serotonin is credited with maintaining a sense of “happiness” by helping to keep the mood stable. It calms anxiety, relieves feelings of depression and aids a good night’s sleep.


As a neurotransmitter, it directs nerve impulses between the brain and other locations in the body and back to the brain. Serotonin concentrations are highest at important sites in the central nervous system.




GABA is a neurotransmitter (like serotonin or dopamine) and therefore sends chemical messages through the brain and nervous system. In other words, it participates in the communication between neurons.


GABA’s role is to inhibit or reduce neuronal activity, and it plays an important role in behavior, cognition, and the body’s response to stress. Research suggests that GABA helps control fear and anxiety when neurons become overexcited.