The Physiology of Love


Most of us can look back at a time in our lives when we have felt “butterflies” in our stomach, or felt ourselves “falling” for someone. We may experience ourselves getting a bit obsessive, and some have described their feelings as “going crazy” for that person. Though these seem like just exaggerated words or phrases we have come to use, there seems to be some truth to these thoughts and behaviors.  Where are these sensations, obsessive thoughts, and often out of character behaviors coming from? How does our physiology actually change as we find that special person? According to neuroscientists, the process of falling in love is very similar to that of addiction. Romantic love releases neurotransmitters in the brain, just as it would if the person were experiencing a high. When you find yourself attracted to another person, or experiencing that chemistry or connection, you crave to be around them the way you would crave a drug. In this process, the neurotransmitter Dopamine surges, creating a great feeling of euphoria when you are around that person, or even when you think about them. You’re then left craving that feeling again, or chasing that high.

Simultaneously, Serotonin levels, which are associated with mood, begin to drop, leaving us desiring that person even more intensely. Neuroscientists have found that these dropped levels of Serotonin are responsible for the obsessive behaviors and “crazy” feelings in the earlier stages of romantic love. Interestingly, depletion of Serotonin is common in Depression, Obsessive- Compulsive Disorder, and Anxiety. In fact a study by Dr Donatella Marazziti, a psychiatrist at the University of Pisa, showed that individuals who were deeply in love with their partners for six months, had the same levels of Serotonin as her patients who were suffering from Obsessive- Compulsive Disorder.

Our bodies also respond to romantic attraction with a strong release of Adrenaline and Cortisol--the stress hormones. This release makes our palms sweaty and our hearts race when we unexpectedly run into our beloved.

The physiological impact of romantic love intensifies as we become more intimate with our partner. The hormone Oxytocin, which is released by both men and women during orgasm, deepens and strengthens the feelings of attachment to our partner. It is believed that the more a couple sleeps together, the stronger their bond becomes. The molecule CRF (corticotrophin-releasing factor), meanwhile, is released when we are away from our partners for too long. This molecule is associated with negative and unpleasant mood, and can lead to separation anxiety.

What then happens to these neurotransmitters and hormone responses when we have been with our partner for many years? Anthropologist Helen Fisher explains that love has two distinct stages: (1) Attraction (passionate love) and (2) Attachment (Companionate love). While the process of falling in love leaves us feeling elated, obsessive, or even moody, being in an established committed relationship is associated with calm content feelings and most often, an absence of anxiety. Studies show that as love progresses, neurotransmitters like Dopamine begin to drop and neurons in the Limbic system become habituated to our surroundings. Simultaneously, our endorphin systems take hold, giving us feelings of tranquility, stability and safety in our relationships. The feeling of elation typically subsides anywhere between 18 months and three years.

As neuroscientists continue to study the impact attraction, romantic love and attachment have on our physiology, it becomes clear that we don’t just love with our hearts and our minds, but in fact love is a full body experience that can actually alter who we are and how we function.