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Cuddle chemical. Love hormone. Moral molecule. These all sound more like magic love potions than real-world science, but these are all nicknames for a very interesting brain chemical: oxytocin.

Oxytocin has gotten a lot of press in the past several years as the magic ingredient behind so many inexplicable feelings we have—and particularly, feelings women have. She barely knew the guy and can’t get over him? Oxytocin. The inexplicable feeling of belonging between a new mom and her babe? Oxytocin. Why so many women love to have their hair brushed? Oxytocin.

Even more interesting, perhaps, is that despite oxytocin being present in both women and men, it seems that women have a lot more opportunities than men to experience this feel-good chemical. Could it be that women, who arguably have the short end of the hormonal stick with PMS, pregnancy, and menopause, actually have an advantage in this particular arena?

Well, it turns out, the analysis isn’t quite that simple. Larry Young, a researcher at Emory University tells me that, yes, women have more opportunities to produce oxytocin by virtue of the fact that they give birth and breast-feed, whereas men cannot. But there are also some relationship tendencies at play that give women an edge on the hormone. Young points out that because women tend to be more communicative and may have more friends than men, they have more social opportunities for oxytocin to be produced, although not always in positive ways.

So we know it’s there, and we know it impacts us in many unique and interesting ways, but what’s the real story about this mysteriously powerful hormone?


Oxytocin has always had a strong association with women. It was discovered in the early 1900s, and its name comes from two Greek words meaning “swift birth,” from one of oxytocin’s basic functions: facilitating childbirth. During labor, our bodies naturally release large amounts of oxytocin, which helps the uterus contract. The hormone is also administered by doctors in its artificial form, pitocin, as an aid to induce or keep contractions progressing during labor.

When it’s time to feed that beautiful newborn, oxytocin is there to help by triggering milk letdown. It also helps a mother and child bond. Oxytocin production is stimulated through warmth and touch—like when a mother holds her newborn.

But you don’t have to be a mother to experience its effects. As one would expect from something called the “cuddle chemical,” both men and women release oxytocin during sex. Things such as eating or the stimulation of olfactory senses have also been correlated to oxytocin release. As for touch, researchers at Cedars-Sinai did a study in which one group was subject to forty-five minutes of “light touch,” while another group got deep-tissue Swedish massages. While the deep massage decreased cortisol levels, the light touch released more oxytocin. According to some, even just thinking about someone you like can trigger oxytocin.

“Oxytocin is released when people have a sense of connection,” Young says. He studies oxytocin in voles, a small type of rodent, because of the critter’s monogamous tendencies. As Young puts it, oxytocin “enhances the salience of social interactions.”


Oxytocin isn’t all cuddles and joy though. According to some research, oxytocin can enhance negative social cues. As psychologist Shelley Taylor explains in an article published by the American Psychological Association, oxytocin doesn’t just increase in women in good relationships; it can also increase in women in unhealthy relationships, perhaps as a signal to seek close connections elsewhere. Young explained that when you consider someone to be part of your group, oxytocin can trigger social behavior toward them. But if you see someone as an outsider, the oxytocin won’t bring you any closer. It may trigger anti-social behavior instead.

And although nursing your newborn, holding your husband’s hand, or gazing into the eyes of your boyfriend can trigger oxytocin, so can stress—especially socially related stress. Brian Trainor of UC Davis explains that there are many studies of instances in which oxytocin increases the level of anxiety in both humans and animals, and that’s something that needs more exploring.

In blood samples of women with PTSD and depression, Trainor says oxytocin levels are elevated. Usually, people think of this as a coping mechanism because oxytocin works to foster social connections. But in some cases, oxytocin can trigger avoidance.

In his research, Trainor and his colleagues found that oxytocin prompted depression-like symptoms in female mice. Usually, he explained, mice are social—they’ll go check out unfamiliar mice. But the stressed mice in his study withdrew. He gave them oxytocin to see what would happen, and the results between males and females were strikingly different. In male mice, the boost of oxytocin increased their social motivation. But it didn’t help the female mice—even with the extra oxytocin, they avoided new social situations and continued to act stressed. Then, he tried blocking the oxytocin receptors, which suppressed the oxytocin. And surprisingly, they acted normal. While the boost of oxytocin helped the male mice, blocking oxytocin was more helpful for the females.


Karen Bales, a researcher at UC Davis, explains that it was the high oxytocin levels in new mothers that first drew attention to oxytocin for its role in forming bonds, an area of oxytocin research that seems to have taken off in recent years. A 2005 paper in the journal Nature garnered significant attention by showing that inhaling oxytocin increased trust. Another study tested the likelihood of monogamous men to bond with an attractive stranger. Yet another looked at how men would rank pictures of their romantic partners when compared to pictures of other enticing people. The studies seemed to point to oxytocin as an aid in faithfulness and morality.

One researcher, Dr. Paul Zak, earned the nickname “Dr. Love” for his study of the subject—and his frequent hugs (he recommends eight a day). He describes a boost in oxytocin as a “positive loop.” He explains that when we do something for another person to boost their oxytocin production—for example, hug them—they reciprocate with something that boosts ours. It's “a gift” we give others, he says.

Yet Zak’s research that claims oxytocin is the reason why we are moral has been criticized by some for oversimplifying oxytocin’s role. At the heart of the controversy over behavior change studies in humans is the role of intranasal sprays in conducting research. Since Zak’s original study, several researchers have continued experimenting with nasal oxytocin to no avail, or at least not the extent of success that Zak describes.

Bales points out that Zak was among the first to use intranasal oxytocin in humans, and that when his findings were published in the early 2000s, scientists didn’t know as much about oxytocin then as they do today. That’s the thing with science—sometimes, our understanding changes as new discoveries are made.

Part of what makes understanding oxytocin so complicated is that the effects can vary. There are different results depending on species, sex, situation, environment, and other hormones—and there are lots of other hormones at play. What happens with oxytocin really depends on the context.

One of the hormones that works in tandem with oxytocin is dopamine. Young explained that oxytocin makes us more attentive to the features of the people we love, and dopamine is a pleasure chemical. When the two work together, our brains connect pleasure with people.

Another hormone that has some interplay with oxytocin is vasopressin. While oxytocin increases bonding and is connected to nurturing, vasopressin increases vigilance and territorial tendencies. People used to think that oxytocin was only in women, while vasopressin was only in men. Both hormones are present in males and females, but men have higher levels of vasopressin than women do. 

It can be hard to say how all this oxytocin research fits together—there are still a lot of mysteries to be solved and questions that need to be answered. “This is not a field that condones itself to easy answers,” Trainor says.

Bales explains that when we’re talking about oxytocin, we have to really consider how much an unnatural source, such as a nasal spray, could with long-term use alter our natural systems. “We just need to go forward cautiously when it comes to using oxytocin in clinical contexts,” she says.

When looking at the big picture of oxytocin, it seems like there are a lot more questions than there are answers to the hype. “Oxytocin is kind of involved in everything,” Bales says. “And it’s a lot more complicated than people generally realize.”

Oxytocin helps us birth and feed our babies and connect with our spouses. It can drive us closer to some people but push us away from others. It’s part of the joyful times but also times of stress. And there’s a lot we still don’t know. Oxytocin is no “Love Potion No. 9,” and it's important that we realize the nuance of it all. But there’s certainly something to be said for the beautiful complexity of our bodies, and oxytocin ranks as one of the more fascinating elements.

Photo Credit: Ashley Paige Photography