Oxytocin: It's Not Just The 'Love' Hormone After All

If you're like most people, you associate oxytocin with love. That's fair—oxytocin's nicknames do include the "love" hormone and the "cuddle" hormone, after all. Oxytocin gets its nicknames because it's associated with several different feelings of bonding, closeness, and love.

In scientific terms, oxytocin is a neurotransmitter and hormone produced in the hypothalamus and secreted by the pituitary gland. It is commonly referred to as the "love" hormone, but its role in the body goes well beyond what you might immediately associate with love. While oxytocin is associated with increased sexual arousal in both men and women, it does a lot more than trigger feelings of romantic love.

Oxytocin also plays an important role when it comes to the memory of faces, or social recognition. This doesn't just apply to people you love (or even like), but to people in general. While oxytocin can increase people's memory of faces, it has an amnesic effect2 on both men and women when it comes to other kinds of memory. When oxytocin levels are increased, for example, men and women may both find it more difficult to recall things like vocabulary. So if intense feelings of love have ever left you feeling speechless, that could be the reason behind it.

Yet another positive effect of oxytocin is anxiety relief3. This also makes sense; love, in its purest, wash-over-you form has a calming effect. In both men and women, increased levels of oxytocin (whether triggered by feelings of love and cuddles or something else) are linked to feelings of reduced stress and anxiety.

Anxiety relief isn't oxytocin's only positive impact on mental health. The love hormone has also been shown to be correlated with lower rates of depression. This is because people with lower levels of oxytocin are less likely to find social interactions enjoyable, making them more susceptible to depressed feelings. In the simplest terms: More oxytocin might make you happier—or at least increase your capacity for happiness.

Oxytocin is released while hugging, leading to its nickname, the "cuddle" hormone. Also called the "love" hormone, oxytocin is associated with several different kinds of physical affection. People in the early stages of romantic relationships have more oxytocin than single people. When people in the early stages of a relationship engage in things like warm touch (which could mean anything from a hug to couch cuddles to gently touching your partner's arm), oxytocin is released and signals the pleasure centers in the brain. This is key to the process of developing romantic attachment5.

Sexual activity5 also causes the release of oxytocin. Particularly, arousal and orgasm are associated with the hormone.

In spite of its wide range of functions in the human body, for many, oxytocin is still most closely associated with romantic love. That might be an incomplete picture of oxytocin's role, but it's not incorrect; oxytocin is released during intimate moments, like during hugging and orgasming. In both men and women, sexual arousal and orgasm bring an influx of oxytocin.

When it comes to romance, oxytocin doesn't just increase during moments of explicit sexual activity or physical touch. In 2012, researchers found that oxytocin levels were higher among people in the early stages of romantic attachment (you know, the so-called honeymoon phase) than they were compared to unattached, single people. And if you're wondering just how long the honeymoon period lasts, science would suggest it's about six months—that's how long the newly coupled-up enjoyed a boost of oxytocin levels.

While oxytocin definitely affects men, years of research into the hormone have shown that its impact on women is much greater. This is due, in large part, to the pivotal role oxytocin plays in pregnancy and postpartum bonding between mothers and babies.

Oxytocin plays an important role in just about every stage of female reproduction, from sexual arousal to labor and breastfeeding. A mother's oxytocin levels during pregnancy can affect her future relationship with her child. Women with higher plasma levels of oxytocin during their first trimester of pregnancy have been found to have stronger bonds with their children after birth. Women who have higher levels of oxytocin throughout their pregnancy and just after childbirth are also more likely to form unique bonds with their children by developing special routines that only the mother and child share.

During labor, oxytocin is responsible for causing contractions in the uterus, and oxytocin levels continue to increase in women as their cervixes and vaginas widen to prepare for delivery. The increased oxytocin produced as the cervix and vagina widen leads to even more contractions, which keeps the process of childbirth on track. For this reason, oxytocin has long been used to help induce or augment labor8. After labor, oxytocin can also be used to control bleeding and prevent postpartum hemorrhaging.

Yes, men do naturally produce oxytocin, but women typically produce more. If there's one thing that rivals oxytocin's fame as a hormone triggered by romantic love, it's the hormone's pivotal role in childbirth and breastfeeding, which are both, obviously, unique to women.

That said, oxytocin definitely has an impact on men. When it comes to bonding and relationships, studies have shown that oxytocin can make men feel more monogamous. In one notable study, heterosexual men in committed relationships were given a nasal dose of oxytocin before being shown pictures of their partners as well as pictures of other women, including some long-standing acquaintances. With the extra oxytocin flowing in their systems, the men found their partners more attractive than other women, and brain scans revealed that the reward system of their brains lit up when they looked at pictures of their partners.

This could mean that oxytocin promotes monogamy by turning our romantic partners into, essentially, a very personalized drug. The reward systems that were triggered by the photos of the study participants' partners are the same ones that would light up for an addict taking a dose of their drug of choice. So when you hear people say that love is their drug, they're not just being cringingly cute; they might just be scientifically accurate. This also explains why people are prone to depression when they lose a partner, whether it's to a tragedy like death or a simple breakup. The sudden decrease in levels of oxytocin doesn't just make a recently single person less happy, it actually has the ability to send the recovering love addict into a withdrawal state.

The fact that the photos of the "long-standing acquaintances" (friends, colleagues—women the men had known and interacted with regularly for years) didn't trigger the same reward centers in the brain shows that it's not just being familiar with someone that makes oxytocin work its magic. This addiction response requires an actual bond of love.

Shifting away from romantic love, increased oxytocin in men has also been shown to make fathers play and bond more closely with their children. In one study, researchers brought in fathers with young children between the ages of 1 and 2. The study participants were either given a dose of oxytocin or a placebo (both were given as researchers' trusty old favorite oxytocin delivery system, a nasal spray) and then shown pictures of their own kids, a kid they had never seen before, and an adult they had never seen before, all while undergoing functional magnetic resonance imaging (fMRI). When the fathers who had received a dose of oxytocin looked at pictures of their own children, the reward and empathy centers in their brains lit up.

In another study, fathers of 5-month-old babies were administered oxytocin and then, after a period of separation, reunited with their infants for play time. The fathers who were given a boost of oxytocin experienced improved social bonding with their children. The fathers themselves were more engaged in the play and, interestingly, the infants' oxytocin levels also rose, and the babies exhibited an increase in baby bonding behaviors, like social gaze and exploratory behavior.

There's still a lot to learn about oxytocin's effect on the body and brain.

One thing that we know about oxytocin is that it is closely associated with stress and anxiety. When we're especially happy (like when we're feeling head-over-heels in love), we're brimming with oxytocin. But when people are stressed, they also exhibit increased levels of oxytocin. How can this possibly be? More oxytocin when we're feeling great and when we're feeling quite the opposite? It seems like a paradox, but it's really not.

What it comes down to is that oxytocin levels are correlated with feelings of well-being. Assume that you have a base level of oxytocin when things are just OK—not great but not bad either. When something great happens and your oxytocin levels rise as a result, you feel awesome. In those cases, the people who feel the best and have the happiest things happening in their lives (like people who are in love or new parents who are bonding with a baby) will have the biggest boost of oxytocin. In periods of intense stress, however, the body also might be triggered to produce extra oxytocin above and beyond that base level to stave off the negative effects of stress.

Researchers have different hypotheses about why this might be. One school of thought suggests that the body increases oxytocin during stress to help us stand our ground during moments that would normally trigger flight or fight. During childbirth, there are plenty of reasons to be stressed, but neither running away nor fighting back against what's happening would be at all useful for addressing it. The same effect might be triggered by stressful events for which societal conventions don't encourage flight or fight. During a critical review at work, for example, it's not considered appropriate to bolt out of your boss's office or to haul off and punch him. Infusing your bloodstream with extra oxytocin might be your body's way of helping you stay put and tolerate stress.

Another theory suggests that during times of anxiety or depression, the body might produce more oxytocin in order to encourage social bonding. Elevated levels of the hormone might prompt anxious or depressed people to seek out human contact, which would alleviate stress caused by social deficits, or explain why you feel good when surrounded by supportive friends.

On the happy side of the oxytocin equation, studies have shown increased levels of the hormone to be correlated with higher reports of life satisfaction and lower levels of depression. What's not clear, however, is whether the correlation is also proof of causation. It remains to be seen if producing more oxytocin makes people happier or if happier people just naturally produce more oxytocin.

Oxytocin also has other positive effects on the brain. Taking extra oxytocin has been shown to improve self-image10 and people's perception of their own personalities. Increased oxytocin is also associated with an array of happy feelings, like warmth, trust, and openness.

If you're looking to encourage your body to increase the amount of oxytocin it's releasing into your system, you can go for some of the known triggers for natural production, including hugging (try the 20-second hug), sexual activity, and nipple stimulation6 in women.

Other nonsexual and non-physical activities that give you a rush can also increase oxytocin, particularly social activities. For example, one recent study found that engaging in gossip can increase your oxytocin levels13. The more you know, right?

Low levels of oxytocin can be particularly disruptive for pregnant women or new mothers6. In pregnant women, lower-than-normal levels of oxytocin can result in labor issues (including a need to be induced or an increased risk of postpartum hemorrhage). For new mothers, low levels of oxytocin can cause lactation issues.

Researchers are looking into many possible therapeutic uses for oxytocin. There is evidence that suggests it could be used to treat anxiety and depression—although that evidence is far from conclusive. Despite the fact that oxytocin levels are most certainly associated with feelings of anxiety and depression, there is little evidence14 that supplements of the hormone cause a significant improvement in these conditions, and some even fear it could make them worse.

Other possible therapeutic uses for oxytocin include the treatment of autism and Asperger's11 in adults and irritable bowel syndrome (IBS)15. There is also research that suggests oxytocin might be used to aid in muscle maintenance and repair in old age.