The Brain of a Loving Person: Biochemistry of Passion and Kaleidoscope of Hormones

The Brain of a Loving Person: Biochemistry of Passion and Kaleidoscope of Hormones

Despite the fact that the air of romance surrounds human relations, scientists have known for a long time that hormones drive it all. They cause shining eyes, the lack of sleep and appetite, elation. Like other feelings, love goes through several stages, from total euphoria to indifference toward a once dear person.

Three stages of being in love: from passion to friendly disposition

Three stages of being in love: from passion to friendly disposition

Recent researches have shown that the emotional component of relations goes through three stages: lust, attraction, attachment. Each stage is characterized by certain chemical reactions. When you are in love, your body produces a great number of hormones that have an effect on your feelings and behavior. Let us view every stage in detail.

The first stage of being in love: lust

The body maintains this feeling thanks to such sex hormones as estrogen and testosterone. Both male and female bodies have them in different proportions. Production of hormones causes the arousal of sexual desire for someone. At the same time, the processes that take place in the brain reduce stress and ensure a rise in vigor. This stage lasts for around half a year and is characterized by a burst of activity and emotions. It is tapped in the human body evolutionally and is responsible for the want to produce offspring.

The second stage: attraction or passion

Lust gives way to romantic feelings toward the object of affection. At this stage, we write poetry and songs, dream about our love mate all day, and make insane actions in order to impress our partner. The stress level goes up drastically at first; adrenalin and dopamine are produced actively. At the physical level, you experience such symptoms as fast heartbeat, sweating palms, and jumping thoughts in the presence of the significant other. In some time, the level of hormones goes down, and the intensity of emotions declines. This phase lasts for a year to three years.

Third stage: attachment

Usually, couples that have been together for several years come to this stage. Steady attachment to the partner, willingness to take care of and strengthen relations are common for the stage. Many couples feel they want to conceive a baby at this stage. Actions of each partner are aimed to create a shared space where loyalty and respect come first. Romance and passion go down at this stage. Such hormones as oxytocin and vasopressin are produced during this period.

Hormones control all of us: when the mind loses the game

Hormones control all of us: when the mind loses the game

At all of these stages, our body produces different hormones that have an impact on our behavior and wellbeing. Let us view each of them in detail.

Testosterone and estrogen

These sex hormones control our behavior during the first stage of love. Testosterone (roughly speaking, a male hormone) makes us behave more actively, smoother, stimulates sexual desire. Estrogen is classified as a nominally female hormone (meaning that men also have it but in small amounts). It is responsible for the expression of sensualism, tenderness, elation.


This hormone is actively produced during body fondling. It is made in the hypothalamus, forms an emotional attachment, as well as a deep feeling of love and loyalty. Oxytocin makes the person feel sensitive and sentimental, caring, attentive to how the partner behaves. It is responsible for building trust relations and the intimacy that lovers long for. Another important function of this hormone is to build a stable emotional bond between the mother and a child. The production of oxytocin after childbirth helps the mother to forget about the pain and to feel tenderness to the newborn.

The unpleasant sides of the “oxytocin storm” are poor concentration, memory, cognitive capacity.


A complete opposite of oxytocin. It facilitates a sharp improvement in memory and concentration, makes us feel hostile to “strangers”. At the physical level, it constricts the blood vessels, increasing pressure. Vasopressin has an impact on building a stable connection with the partner, makes us restrict contacts with the opposite sex to some extent, as well as pay the maximum attention to the significant other. This hormone is produced by the hypophysis.


It is produced in the hypothalamus and atrabiliary capsules. It relates to the so-called “feel-good” hormones. Dopamine “anchors” the behavior that is preferable for the body, building the habit. When you are full of energy and intention to act – this is it. One can safely say that this hormone is an all-powerful motivator. Its production starts not even during the action that brings pleasure but at the stage of thoughts about the upcoming action. In case it turns out to be just as pleasant in reality as in dreams, the production of dopamine is anchored for this kind of action. In such a way, stable behavior is formed.


This hormone can be found in all body tissues and organs, including blood. Serotonin facilitates mood improvement, an increase in the heart rate, and a lack of hunger. The sexual desire for the partner grows. When you notice that you are thinking about your significant other every minute – it is a consequence of intense serotonin production.


One of the stress hormones. When it enters the blood, your breathing gets faster, the face goes red, and you start sweating. It is produced especially actively in case the object of love is not beside you. Cortisol reduces appetite and keeps the nervous system on edge. The excess of cortisol can lead to chest pain and aggravation of chronic diseases.

All hormones can be present in various combinations, causing many emotional reactions.

Fidelity gene: is it possible to love one partner within the whole life

Hormones control all of us: when the mind loses the game

It is not a secret that some people find it difficult to maintain fidelity to one partner. Is such behavior a trait of character, a result of parenting, or wholly owned to the release of a big amount of certain hormones in blood? Let us analyze why some people are monogamous, and others cannot limit themselves to one partner.

Scientists researched the issue of polygamy through the example of field mice. It turned out that mice had two types of dopamine receptors – let us call them D1 and D2. The latter is responsible for attachment. If you block these receptors, the field mice will become aggressive.

After the male mouse develops a mutual attachment to the female mouse, the number of D1 receptors starts growing in its brain. Dopamine is produced, contributing to the development of a positive connection. As a result, the brain of the male mouse changes in a way to make it monogamous.

Polygamous mice show another situation – the initial number of D1 receptors is high for them. Moreover, meeting a certain female mouse does not increase this number. For this reason, an attachment to one mouse does not develop.

An interesting fact is that scientists assume the presence of similar mechanisms in people. Those of us who produce a high level of vasopressin are more prone to monogamous relations.

Such research gives ground to further work on the regulation of the hormone levels. This would allow people to get rid of the discomfort related to a broken heart, betrayal, or a loss of interest in the partner.

You can learn more about emotions and methods to manage them at Biohacking Conference Kyiv, which will take place on March 26. At the conference, the Doctor of Biological Sciences Nana Voytenko will make a presentation titled “Brain and emotions. How to preserve health and fight stress”.

Please rate this news:
(75 votes, average: 4.3 out of 5.)

Buy a ticket
Learn about new speakers and key news of the conference