People like having sex. That much can be said for the majority of the population. But how, exactly, sex impacts mood is much more complicated. "People seem to write about sex as though it's this incredibly specific, very clear thing in the brain that we can point to and know when someone is sexually aroused," says Nicole Prause, associate research scientist in the Department of Psychiatry at UCLA. In reality, Prause says that areas of the brain that activate during sex are very similar to those that are active during other rewarding situations, like eating chocolate or playing with puppies.
Adding to the research hurdles, says Prause, is that fact that scientists in the U.S. are not permitted to research the positive effects of sex. She says that is why you don't see studies about the (probably obvious) impact of orgasm on insomnia. So, while all of us likely have solid ideas of what sex does to our mood, we'd be hard-pressed to find scientific back-up. "There is every reason to think that it has lots of positive mood effects and could be helpful, especially for depression, but we don't know that for sure," says Prause. "We haven't demonstrated it." If you have read about sex boosting mood, it is likely not a specific study but an assumption based on the release of hormones that occurs as a result of sexual activity.
The hormones at play are dopamine and oxytocin. Dopamine is released anytime something is pleasurable. Whether you enjoy sex, a good meal, or gambling, if it's something you want to do again, dopamine is involved. Oxytocin, often mistaken as a strictly romantic hormone, plays a big role in feelings of bonding and affection. This can, of course, involve romance but also applies to familial and friendship-related affections. Both of these feel-good hormones surge during sex and particularly after orgasm.
"There's not much that's more reinforcing than orgasm," says Rebecca Burch, associate professor in the Department of Psychology at SUNY Oswego. If it were only these hormones that determined how sex impacts us, then, yes, good sex would likely put us in a good mood.
Learning about sex hormones and mood inevitably brings up research (that Burch co-authored) that is so spectacularly popular that people still bring it up regularly, although it is over a decade old. This study dove into the intricacies of seminal fluid and found that vaginal exposure to seminal fluid was related to lower levels of depressive symptoms. Looking at various chemical compounds in seminal fluid, the researchers hypothesized that exposure to seminal fluid may have implications for fertility, such as bettering the mood of a potential mother, but also helping to improve the chances and maintenance of pregnancy. More research would be needed to confirm and expand upon these findings.
To be clear, Burch's research said nothing about oral exposure to seminal fluid, which is likely extremely different because of the route of exposure. It also does not advocate for unsafe sex. Even if seminal fluid can improve mood, that is no reason to ditch your condoms. "Pregnancy can be very depressing, if that's not what you want," says Burch. "Herpes is, of course, going to be very depressing."
We may not be able to say much that is definitive about the effects of sex on mood but we do know that mood is can definitely affect sex. Studies have shown that even strong physical stimuli — vibrators on genitals kind of strong — may not arouse people who are distracted. Men who were hooked up to vibrators and shown erotic imagery often have sexual responses but those responses are dulled if the men are, for instance, asked to solve a math problem at the same time. In the real world, this could relate to the difficulties in sexual dysfunction that some people experience when they are stressed or distracted by performance anxiety. Depression is also known to affect people's sex drive and functioning. For this reason, Prause suggests that people may need extra help getting aroused in situations where their mood is low or negative. "It may not always be as automatic as we thought," she says. "A little assistance may go a long way." Examples of things that may help include erotic imagery or videos, fantasizing, or trying to be intimate gradually.
No matter what kind of research is done, it is highly unlikely that sex will come out as a magic bullet mood booster. It just isn't that simple. Bad sex or sex for the wrong reasons is not going to improve someone's mood. Great sex with a partner who doesn't want a relationship but you do is probably not going to get you to a happy place either. Mediocre sex that still gives a needed ego boost, on the other hand, could improve a person's mood a lot. There is nothing wrong with sex making you happy but, in reality, it's more than just the sex, it's the context too.