The Chemistry of Romantic Love

two hands with fingers touching to form heart

How the Chemistry of Romantic Love Affects Your Relationships

Have you ever wondered why we fall in love? Or why you always seem to say the wrong thing around your crush? Or why you just can’t stop thinking about the guy who took you to dinner? Did you know there’s actually a biological explanation for the “symptoms” of falling in love?

Wired for connection

Our brain is built to reward us for behaviors that are good for us, or that have been good for us. These behaviors release a neurotransmitter called dopamine, affectionately known as “the feel good” neurotransmitter. Because, well, it makes you feel good. When we’re attracted to someone, being with them, or even thinking about them, dopamine is released in our brain. In other words, our brain is rewarding us for having a crush.

Elizabeth Kane, who teaches psychology and behavioral science at South University, says that the “human brain supports falling in love, which is why we have such a strong physiological response when we are attracted to another.”1

Dr. Daniel G. Amen, psychiatrist and brain health expert, describes love not as an emotion but as a motivational drive, much like being hungry. It’s no wonder that we go to parties, make dating profiles, ask our friends to set us up, and are willing to go on dates with lots of duds before we find that special someone. Our brain is designed to find love!

Wired to fall

Once we perform a behavior that releases dopamine, our brain motivates us to perform it again, through use of a neurological reward circuit. That’s how we learn new behaviors. As infants, that’s how we learned to eat, cry, and suck on our pacifiers. As teenagers and adults, it’s why we can’t stop thinking about our new crush or significant other (S.O.). Our brain recognizes that thinking about them releases dopamine, which, because it triggers the reward circuit, motivates us to think about them again, and again, and again. Furthermore, falling in love seems to decrease our levels of the neurotransmitter serotonin, a state associated with obsessive compulsive behaviors. So next time your friends complain that you talk about your new S.O. too much, tell them it’s not your fault; it’s biology.

Changes in dopamine and related chemicals, such as serotonin and cortisol, cause other familiar side effects associated with falling in love. Inability to sleep, nervous sweating, increased heart rate, euphoria and anxiety can all be blamed on the chemical brew dripping from Cupid’s Arrow. And all of those clumsy moments? All of those times you said something incredibly embarrassing in front of your crush? You can blame those on your brain, too.

Unfortunately, just when we need it most, when we’re attracted to a person, our brain tends to shut down the areas responsible for “critical thinking, self-awareness, and rational thinking.”2 Thanks a lot, brain. This process is also responsible for the “love is blind” phenomena, where we fail to see the flaws or shortcomings in our new partner–although maybe this side effect is a good thing during those precarious early stages of romance.

Wired for commitment

Falling in love is exciting. It’s a time when a confusing blend of giddiness, anxiety, and hope all swirl together in an often breathless, embarrassing, and exhilarating whirlwind. But what happens once we’ve fallen in love? As wonderful as falling in love is, this whirlwind would be an impossible state to maintain. Constant distraction, preoccupation, and anxiety over this tender new romance could prevent us from living our daily lives.

Thankfully, our brain does not maintain this heightened state forever. Over time, levels of cortisol and serotonin, responsible for preoccupation and anxiety, return to normal. Dopamine and the reward circuit, however, are still active as the relationship continues, making time with your S.O. just as fulfilling.3

Oxytocin, or the “love hormone,” is also important during these later stages of romance. Its effects largely have to do with bonding and attachment, also acting as an antidepressant and creating a sense of security and trust. Oxytocin is largely known for its role in maternal-infant bonding, and is released during both childbirth and breastfeeding. In addition to these crucial functions, oxytocin is also released during any type of skin-to-skin contact, from holding hands to having sex.

In other words, physical touch actually heightens feelings of attachment to a person. Many scientists propose that this is why “casual sex” often tends to not be so casual. No matter our intentions before a hook-up, with each physical encounter biology is set in motion and oxytocin is released which bonds us to our partner, dopamine levels are spiked and our minds associate the hook-up with falling in love.4

Keeping love alive

What happens once we’ve been in a relationship for a while? How do we keep ‘love’ alive? After all, cortisol and serotonin levels return to normal; is it even possible to retain that giddy feeling of new love? The good news: MRI scans show us that the parts of the brain that light up when couples in the throes of early romance view their romantic partner are the same as those that light up when couples who have been together for decades view their partner. In other words, love can definitely last.

One tip for keeping love alive involves what we know about dopamine. Dopamine release is triggered by novelty and unfamiliarity.5 Consider a date that involves something you and your partner have never done before. Going to a new restaurant can help rekindle the romance, but research shows that doing something exciting together is especially effective. This is because we tend to attribute the effects of excitement, such as elevated heart rate and giddiness, to the person we are doing the activity with, instead of the activity itself.6

In addition to dopamine, we know that oxytocin bonds us to our partner and heightens our feelings of attachment. So how do we raise levels of oxytocin? Simple: we touch. Physical touch such as holding hands, cuddling, and kissing all increase our attachment to our partner through the effects of oxytocin. If you’re feeling distant from your partner, the simple solution may be to get close.

Stay in touch

There you have it: the biological facts (and hacks) of romance. Our brains our wired to find love. Our search for romance is as natural as our need to eat or sleep. Once we make a connection with someone, the chemical brew including dopamine surges and serotonin depletions create the exhilarating and awkward madness of new love, and as the relationship progresses, oxytocin steps in to calm things down with secure attachment and trust.

Even with the “here’s why” of romantic chemistry, love and relationships can still seem impossible and confusing. Follow us at @a2woman on Twitter and Instagram to stay up to date on our upcoming blogs about relationships.


1 University, S. (2012, January 30). The Psychology Behind Love and Romance. Retrieved June 15, 2017, from https://www.southuniversity.edu/whoweare/newsroom/blog/the-psychology-behind-love-and-romance-70700
2 Wu, K. (2017, February 14). Love, Actually: The science behind lust, attraction, and companionship. Retrieved June 16, 2017, from http://sitn.hms.harvard.edu/flash/2017/love-actually-science-behind-lust-attraction-companionship/
3 Edwards, S. (n.d.). Love and the Brain. Retrieved June 16, 2017, from http://neuro.hms.harvard.edu/harvard-mahoney-neuroscience-institute/brain-newsletter/and-brain-series/love-and-brain
4 Fisher, H. (2006, February). Retrieved June 16, 2017, from https://www.ted.com/talks/helen_fisher_tells_us_why_we_love_cheat
5 Zamosky, L. (2009, January 15). The Science Behind Romance. Retrieved June 18, 2017, from http://www.webmd.com/sex-relationships/features/the-science-behind-romance#1
6 Barker, E. (2014, April 15). The Science Of ‘Happily Ever After’: 3 Things That Keep Love Alive. Retrieved June 19, 2017, from http://time.com/62029/the-science-of-happily-ever-after-3-things-that-keep-love-alivea

Iris Proctor
Iris is the director of ArborWoman.