The hormone oxytocin—not to be confused with the opioid Oxycontin—goes by many nicknames: the “love drug,” the “cuddle hormone,” the “hug hormone,” and more.
Oxytocin is a hormone that’s produced in the hypothalamus and released by the pituitary gland, which controls many hormones and hormone glands (including the thyroid and ovaries). Oxytocin's exact role is still not quite understood by researchers—and is often exaggerated in popular culture—but there are a few things we do know about this versatile hormone.
1. Oxytocin is a “pro-social” hormone
In simplest terms, this means oxytocin rewards you for connecting with others. Oxytocin levels tend to rise in response to physical touch with others (such as during a massage), and even from non-physical, positive actions from others, such as signs of generosity.
Despite all of its Cupid-like nicknames, many researchers believe that oxytocin actually creates a sense of trust between humans (which may or may not lead to love and snuggles). This rise in oxytocin helps build social bonds and feelings of attachment … which is especially important for the next two points.
2. Oxytocin helps initiate childbirth
Oxytocin levels rise during labor and cause the uterine muscles to start contracting. This was discovered in 1906 by British physiologist Sir Henry Dale, who found that extracts from a human pituitary gland led to contractions in a pregnant cat. It was Dale who named oxytocin, which came from Greek, meaning “swift birth.”
In fact, synthetic forms of oxytocin are sometimes used as a therapeutic stimulant to help induce labor (or speed it up), according to the American College of Obstetricians and Gynecologists.
3. Oxytocin aids in breastfeeding
When a baby attaches to the nipple, oxytocin levels rise, triggering the milk ducts to release milk. Oxytocin is also believed to help strengthen the mommy-baby bond while breastfeeding.
4. Oxytocin may be involved in sexual activity
Researchers believe that oxytocin is involved in sexual activity, but they don’t yet know how. However, a few studies have suggested involvement:
Female Prairie voles (a type of rodent) release oxytocin during sexual activity, which is believed to be one of the reasons they form monogamous relationships with their mate (one of the few non-human mammals that do).
An article in Physiological Reviews stated that oxytocin injections in male rats led to erections. Researchers have even considered oxytocin as a potential therapy for erectile dysfunction.
A 2011 article on oxytocin stated that concentrations of oxytocin in plasma were higher in people who said they were falling in love.
And of course, you already know that oxytocin levels can rise just from positive physical contact, which sexual activity tends to provide in bulk.
5. Oxytocin may counteract stress
In a fast-paced, high-stress, modern world, it can be hard to appreciate the subtle ways oxytocin works on stress: No naturally occuring amount of oxytocin in the brain will eradicate your feelings of stress about your upcoming work deadline, for example.
Here’s how it works: Oxytocin appears to counteract or balance cortisol, the primary stress hormone. Cortisol has many effects on the body, and is actually positive in small amounts. It can help control your blood sugar levels and reduce inflammation, for example.
However, in large amounts and for longer periods of time, cortisol can take a turn and have negative effects on health, such as by weakening the immune system. (Here are other ways too much stress can affect your health.)
Oxytocin may help keep cortisol levels in balance, so stress levels are less likely to hurt your body. (All the more reason to hit the mattress with your partner after a stressful day, right?)
There’s still a ton to learn about the “love drug,” but it’s clear that humans wouldn’t be the same without it.