How Your Sex Life Affects Your Butt Size

I was 14 when I got my first boyfriend. Essentially, we had two things in common: We were in the same grade, at the same school, and we were both very eager to lose our virginities. I don't remember all that much about our relationship other than skipping class to make out in his parents' basement a lot. I also remember that the day I called up my best friend to breathlessly break the news I was finally going to "do it" that night; the first thing she said was, "Well, your mom's going to find out—because having sex makes your butt big."

My butt has gone through its fair share of phases over my sexually active years—most of them Oreo-related, I suspect—but I never took my childhood best friend's word of warning all that seriously. However, it looks like a lot of people do. If you Google the matter, an endless array of heated forum discussions—Yahoo, Girls Ask Guys, Quora, you name it—will appear.

You'll often see women piecing together that "sex is all about preparing a woman['s] body for pregnancy (duh), so when you have sex, your body is naturally thinking to prepare itself for a child," or claiming that sex makes their hips wider or butt look bigger. Even certain bloggers will tell you that "yes, sex can help your butt grow, but so can sitting in your car on the way to work, because you can squeeze and release those muscles there, too." Although many people in the same forum discussions also dismiss this phenomenon as a myth, there are still plenty who are undecided about whether or not this long-standing butt-growth rumor has legs.

On a basic level, we know that our hormones influence how our bodies look and feel—and having sex alters the hormone levels in our bodies in multiple ways. For one, sex impacts oxytocin, the "love" hormone that's responsible for making us feel all close to our sexual partners; our bodies release it even when we're hugging or kissing, but amount released right before we orgasm is significantly higher. Sex also stimulates the release of dopamine, the "happy" hormone that makes you feel like you have a craving that needs to be satisfied, and when we orgasm, our bodies release dehydroepiandrosterone—which is basically the steroid of all hormones and the driver behind the blissful feeling of an orgasm. There's even speculation in the media that the more often women have sex, the higher their estrogen levels are, and that estrogen can impact your body weight and appearance. Better yet, some recent studies also tell us that even the hormones in semen (testosterone, oestrogen, prolactin, and several different prostaglandin) can essentially be "passed on" to women and affect them both physically and mentally.

So if our own hormones go into overdrive during sex, and if our partners' hormones potentially also affect our bodies, what happens when we send that combination into overdrive consistently? Do our bodies start responding and adjusting in accordance with consistent sex—and in this case, could that response affect the way your body looks?

"No, I don't think that's possible," says Dr. Charlotte Wilken-Jensen, head of obstetrics and gynecology at Hvidovre Hospital in Hvidovre, Denmark. "Sex doesn't stimulate any long-term hormones in the body, so it wouldn't make sense to think that your butt would get bigger because of sex."

According to Dr. Wilken-Jensen, falsely equating short-term hormones with long-term effects is part of the reason women often wonder about the relationship between butt size and sex. However, confusion about the distinct functions of the various hormones in your body is also to blame. "Sure, when you have sex, there's an oxytocin release, which is what makes you hot and what makes the lining of your vagina wet and all that," she continues. "However, oxytocin is not estrogen. Estrogen is what would stimulate your butt to increase in size or change your body composition, and there is no legitimate proof that having sex releases enough estrogen to affect your body in that way."

That said, although having a lot of sex won't make you especially callipygous, it might make you feel that way—and even the feeling could be enough to convince you that your butt is experiencing a growth spurt. Studies have shown that increased sexual activity and sexual satisfaction can significantly alter how a woman perceives her body size. This study, for example, examined 53 recently married couples to find out if sexual frequency and satisfaction could impact the wives' body images, body weights, or physical health. Although the women's body weights and physical health levels weren't affected by the quality of the sex they were having, their body images were: The "wives' perceived sexual attractiveness was significantly positively associated with sexual frequency" and their "perceptions of their body sizes were directly correlated with their own and their partners' sexual satisfaction."

If we believe those results, a lot of great sex won't actually change your body shape, but a lot of great sex will change how you see your body shape. Dr. Wilken-Jensen agrees with this characterization. "When you're more sexually active, it becomes a mental thing—studies have been done on it. You naturally express your body language differently and carry certain parts of your body in different ways," she explains. "Also, it's a no-brainer that sex impacts your self-esteem—which in turn impacts your perception on your body."

So, for anyone out there wondering if their fantastic sex life could come with the delightful bonus of a fantastic, peachy butt, sorry. The hormones flying around your body when you have sex won't actually affect your body shape in the moment, and definitely not in the long run. However, a fantastic sex life will probably make you think your butt looks pretty damn great.