It often elicits an unexplainable sensation — the most enigmatic force that has influenced centuries of philosophical discourse, poetry, and literature. However, in reality, love can be understood through scientific means. The biological choreography of love is not a universally applicable phenomenon. Individual genetic variations, past experiences, and environmental factors contribute to a distinct manifestation of love in each individual.

According to experts who have conducted studies on the science of love, the biological mechanisms behind falling into romantic love can be categorised into three distinct phases — lust, attraction, and attachment — guided by intricate hormonal shifts.

Lust is primarily driven by the desire for sexual gratification, which can be understood from an evolutionary perspective as a means of ensuring the continuation of our species. This phenomenon is not limited to humans, as other mammals on our planet also exhibit similar behaviours. In this process, the hypothalamus, a region of the brain, plays a significant role by stimulating the production of sex hormones, such as testosterone and oestrogen.

When you are in love or attracted to someone, your brain releases certain hormones that are responsible for generating feelings of happiness. These include dopamine, serotonin, and oxytocin.

The initial spark of attraction triggers activity within a region of the brain known as the ventral tegmental area (VTA), which is responsible for experiencing pleasure. Recognising the potential reward that lies ahead, the VTA begins to produce dopamine, often referred to as the "joy and reward chemical," leading to a state of euphoria.

During this growing obsession, the brain sends signals to the adrenal gland, resulting in the production of norepinephrine and epinephrine, which add a touch of excitement.

Serotonin plays a role by stabilising moods, fostering contentment, and establishing a sense of comfort. These chemicals induce feelings of excitement, energy, and euphoria, sometimes even causing a decrease in appetite and insomnia.

In other words, one can be so deeply in love that eating and sleeping become difficult. Particularly, norepinephrine and epinephrine are responsible for the flushed cheeks, sweaty palms, and racing heart that often accompany meeting someone you are attracted to for the first time.

While lust and attraction are predominantly associated with romantic relationships, attachment extends to friendships, social connections, and various other forms of intimacy. In this context, oxytocin, often referred to as the "cuddle molecule," promotes the formation of deep connections and emotional bonds, weaving the fabric of attachment.

Vasopressin, another hormone released after physical touch, contributes to the desire to remain with a particular individual and fosters a strong emotional attachment.

During a relationship cortisol, the stress hormone, may also play a role by introducing tension. Studies have shown that individuals who are in love exhibit elevated cortisol levels compared to those who do not experience such feelings. Nevertheless, the positive effects of the happy hormones ultimately prevail.

It is, however, important to remember that our brain acts as the conductor of this intricate endocrine symphony, expertly coordinating the nuances of love. The brain is hard-wired for love, all the connections are there. The involvement of neurotransmitters and receptors is also pivotal in the process of falling in love.

Throughout history, there has been a romanticised notion that love originates from the heart; it is now understood that contrary to popular belief, it emanates from our brains.

The impact of love differs among individuals due to variations in hormone levels. Research indicates that individuals with high levels of dopamine are more inclined to take risks, whereas those with high levels of serotonin tend to be more cautious in relationships.

Beneath the blushing cheeks lie a series of intricate biochemical phenomena occurring between the brain and the body. Nevertheless, there remains abundant research that needs to be conducted on this topic.

The writer is a medical biochemist working at the National Institute of Cardiovascular Diseases, Dhaka.