• Brandon Roberts

Oxytocin the "Love" Chemical

What causes us to fall "In Love" with someone?

Scientists have been asking this same question for decades. It turns out the science behind love is both simpler and more complex than we first thought. If you Google the phrase “biology of love” you will get answers that run the gamut of accuracy. Needless to say, the scientific basis of love is often sensationalized, and as with most science, we don’t know enough to draw firm conclusions about every piece of the puzzle. What we do know for sure, however, is that much of love can be explained by chemistry. So, if there’s really a “formula” for love, what is it, and what does it mean?


Think of the last time you ran into someone you find attractive. You may have stammered, your palms began to sweat; you may have said something incredibly asinine and tripped spectacularly over your words while trying to saunter away (or is that just me?). And chances are, your heart was pounding in your chest. It’s no surprise that, for centuries, people thought love (and most other emotions, for that matter) arose from the heart. As it turns out, love is all about the brain – which, in turn, makes the rest of your body go haywire.


According to a team of scientists led by Dr. Helen Fisher at Rutgers, romantic love can be broken down into just three categories: lust, attraction, and attachment. Each category is characterized by its own set of hormones stemming from the brain (Table 1).


Sex hormones and how they play a role in reproduction including the laws of lust, attraction, and attachment.
Figure 1: A: The testes and ovaries secrete the sex hormones testosterone and estrogen, driving sexual desire.

Lust is driven by the desire for sexual gratification. The evolutionary basis for this stems from our need to reproduce, a need shared among all living things. Through reproduction, organisms pass on their genes, and thus contribute to the perpetuation of their species.


The hypothalamus part of the brain plays a big role in this, stimulating the production of the sex hormones testosterone and estrogen from the testes and ovaries (Figure 1). While these chemicals are often stereotyped as being “male” and “female,” respectively, both play a role in men and women. As it turns out, testosterone increases libido in just about everyone. The effects are less pronounced with estrogen, but some women report being more sexually motivated around the time they ovulate, when estrogen levels are highest. The important thing to remember is just how big a role this plays in healthy sexual activity.


How Lust, Attraction, and Attachment play a role in how we as humans fall in love.
Figuire 1.

Meanwhile, attraction seems to be a distinct, though closely related, phenomenon. While we can certainly lust for someone we are attracted to, and vice versa, one can happen without the other. Attraction involves the brain pathways that control “reward” behavior (Figure 1), which partly explains why the first few weeks or months of a relationship can be so exhilarating and even all-consuming.


Dopamine, produced by the hypothalamus, is a particularly well-publicized player in the brain’s reward pathway – it’s released when we do things that feel good to us. In this case, these things include spending time with loved ones and having sex. High levels of dopamine and a related hormone, norepinephrine, are released during attraction. These chemicals make us giddy, energetic, and euphoric, even leading to decreased appetite and insomnia – which means you actually can be so “in love” that you can’t eat and can’t sleep. In fact, norepinephrine, also known as noradrenalin, may sound familiar because it plays a large role in the fight or flight response, which kicks into high gear when we’re stressed and keeps us alert. Brain scans of people in love have actually shown that the primary “reward” centers of the brain, including the ventral tegmental area and the caudate nucleus, fire like crazy when people are shown a photo of someone they are intensely attracted to, compared to when they are shown someone they feel neutral towards (like an old friend one has not seen in years).


Finally, attraction seems to lead to a reduction in serotonin, a hormone that’s known to be involved in appetite and mood, among other things. Interestingly, people who suffer from obsessive-compulsive disorder also have low levels of serotonin, leading scientists to speculate that this is what underlies the overpowering infatuation that characterizes the beginning stages of love.


This all paints quite the rosy picture of love: hormones are released, making us feel good, rewarded, and close to our romantic partners. But that can’t be the whole story: love is often accompanied by jealousy, erratic behavior, and irrationality, along with a host of other less-than-positive emotions and moods. You may have had an experience throughout life where these emotions played a role, we all have a story. It seems that our friendly cohort of hormones is also responsible for the downsides of love too.

A couple in disagreement in a relationship.
I think everyone can relate to images like this of a couple in the throws of a heated relationship discussion.

Dopamine, for instance, is the hormone responsible for the vast majority of the brain’s reward pathway – and that means controlling both the good and the bad. We experience surges of dopamine for our virtues and our vices. In fact, the dopamine pathway is particularly well studied when it comes to addiction. The same regions that light up when we’re feeling attraction light up when drug addicts take cocaine and when we binge eat sweets. For example, cocaine maintains dopamine signaling for much longer than usual, leading to a temporary “high.” In a way, attraction is much like an addiction to another human being. The distinction between the two is very slim. Similarly, the same brain regions light up when we become addicted to material goods as when we become emotionally dependent on our partners (Figure 2). And addicts going into withdrawal are not unlike love-struck people craving the company of someone they cannot see.


Explanation of how chemical interactions cause us to behave irrational and think less than logically.
Figuire 2.

And finally, what would love be without embarrassment, or heartache? Sexual arousal (but not necessarily attachment) appears to turn off regions in our brain that regulate and control critical thinking, self-awareness, and rational behavior (Figure 2). In short, love makes us dumb and irrational. Have you ever done something when you were in love that you later regretted? Maybe not you personally, because of course that only happens to me. I’d ask a certain star-crossed Shakespearean couple, but it’s a little late for them.


In short, yes, Oxytocin plays a huge role in us falling in love but it is not the only chemical interaction at play. In the end, everyone is capable of defining love for themselves. With this knowledge, we are all better armed to understand the mechanics of everything behind it.

If you are experiencing a lack in libido, it may be a hormonal imbalance causing it. We offer a very comprehensive diagnostic lab test to help determine the exact levels of not just hormones, but a great over-all picture of vitamins, minerals, and essential amino acids. Give us a call to schedule a Free 15-Minute phone consultation or even an in-office visit. Our contact details are below!



Elite Medical Center

114 Canal Street Ste 201

Pooler, GA, 31322

Office- (912) 988-3839

Email- Brandon@elitemedus.com

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