Every month, your period arrives with the usual suspects in tow: cramps, bloating, fatigue—just to name a few. But it can also bring another (much, much more fun) guest to the party: a wild and crazy libido. So, yeah…it’s no coincidence you feel all kinds of horny on your period.

And that’s despite the fact that you likely don’t feel your absolute sexiest during this time. ICYDK, that particular surge in sex appeal happens during ovulation—about halfway through your cycle, or two weeks after your period—thanks to a slight increase in testosterone, says Dr Mary Jane Minkin, clinical professor of obstetrics and gynaecology at Yale University Medical School.

Okay, so why do I get insanely horny on my period?

While the science isn’t entirely definitive, here’s what docs do know: “The menstrual cycle involves the cyclical rise and fall of estrogen, progesterone, testosterone, and DHEA,” says Dr Adeeti Gupta, an ob-gyn and founder of Walk In GYN Care. (Hence the name “cycle.”) All of those hormones play key roles in your sex drive.

In a 2013 study published in Hormones and Behavior, researchers explored the connection in a group of undergraduate women. They measured hormone levels over two full menstrual cycles and compared the results to daily journals, where the participants recorded sexual activity and feelings of friskiness.

The researchers found that changing levels of estrogen and progesterone had serious effects on libido. Likely because estrogen, which drops at the beginning of your period but then starts to climb steadily by day two or three, promotes libido and desire, explains Dr. Gupta.

Meanwhile, progesterone, a stabilising hormone that is “not sexy-feeling friendly” is at a low point, says Dr. Minkin, so it’s possible that you feel even more sexual in its absence, too.

On the flip side, can arousal affect menstruation?

In short: no. Your hormones are already fluctuating on their own, so sexual arousal has “no major effect” on your menstrual cycle, says Dr Minkin.

Still, “some women report that if they masturbate or have sex, they feel a relief of pelvic congestion or menstrual cramps,” adds Dr Nan Wise, a cognitive neuroscientist and certified sex therapist. (Plus, it feels a heck of a lot better than popping ibuprofen.)

And, of course, your friskier-than-normal feelings can certainly impact your mood during menstruation. Sex and/or orgasm are both known for relieving stress—something you might be subconsciously craving during that time of the month.

“In some cases, women may simply want to have an orgasm to relax and unwind,” says Janet Brito, a licensed psychologist and certified sex therapist in Honolulu. “While in other cases, they may be yearning for an intimate connection. What’s important is to listen to your body and give it what it needs.”

To do that, she recommends keeping a journal on how your menstruation impacts your arousal and vice versa. This, Brito says, can help you get comfortable discussing your needs, promote body awareness, and ultimately enhance your personal and partnered relationships.

Can birth control impact how horny I feel on my period?

You may have heard the long-standing rumour that birth control all but kills your sex drive.

Because hormonal birth control works by stopping your uterus from ovulating, they also stop that little boost in testosterone, so it would make sense, says Dr Minkin.

The Pill, in particular, can affect your libido throughout your menstrual cycle, because it also increases something called sex hormone binding globulin (SHBG).

“If you have some free testosterone running around in your body, SHBG is sort of like Pac-Man,” she explains. “Basically, it just eats the testosterone up, so many people think that’s why birth control can decrease your libido.”

That said, the research is actually pretty divided. In one 2013 study, the majority of contraceptive users reported no significant difference in their horniness, despite their bodies showing a decrease in free testosterone and increase in SHBG.

And in another study, from 2016, women on hormonal contraception reported greater drives for sex with a partner than those who were on non-hormonal types. Meanwhile, women on non-hormonal BC reported higher solitary desire (read: an interest in masturbation).

So it’s possible specific types of birth control affect specific types of sex drives, but science is still confirming. Fascinating.

So is my period horniness **totally** dependent on my hormones?

Nope, not at all! Feeling frisky during your period may also just come down to individual differences, says Wise.

“Women might like sex more or a whole lot less during that time, depending on their physical comfort,” she says. “For some women, when they’re bleeding and crampy, the last thing they want is sex. Others, on the other hand, want sexual activity for relief.”

Your increased desire to have sex on your period could also be tied to a subconscious relief in knowing you’re not pregnant (if you’re not trying to be, at least). You’re also less likely to conceive when you’re menstruating—and there’s “definitely a psychological freedom” in that knowledge, says Brito.

So while your shifting hormones definitely rule the show, your head can get in there too. But if you don’t feel particularly horny during that time of the month, don’t worry: There is nothing—I repeat, nothing—wrong with you.

This article was originally published on www.womenshealthsa.co.za