Menstrual cycles, as we all know, can be difficult and occasionally rather annoying — but they're also a fascinating biological phenomenon that affects different parts of our bodies in ways we're still discovering. If you've ever felt like your period is affecting how much you sweat, some intriguing new science is starting to get to the bottom of why.
Sweat is one of the body's primary ways of regulating body temperature, but it's also closely tied to the hormonal cycle of ovulation and menstruation, and that can have unexpected consequences. Bustle spoke to scientists fromthe period-tracking app Clue about the specifics of sweat and why our bodies adjust their sweating patterns over the course of a cycle.
The relationship between your menstrual cycle and sweat still has a long way to go before we fully understand it, or track exactly how it works. Sweat itself is also a field of scientific interest that keeps producing new discoveries; it was only in 2017, for example, that we found out that tattooed skin sweats far less than non-tattooed skin in young men. You may not think that how much you're sweating matters all that much, nevermind your sweat's connection with your period, but if you find yourself sweatier than usual, there's a possibility your hormones are to blame — and that information is crucial for understanding your health in a holistic way.
1 Your Whole Body Sweats More During This Phase
"Your body’s ability to sweat changes throughout your cycle," Clue scientists tell Bustle. They specifically point to your body's basal temperature — the temperature you might take to measure your fertility — as increasing during the luteal phase, aka the week before your period/PMS zone. Because of this hormonally-driven increase in temperature during the phase where your body moves out of ovulation and gets ready for your period, you'll start sweating more.
"Researchers have noticed that women in their luteal phase show an increase in sweat produced when exposed to warmer temperatures, in comparison to when they were in their follicular phase (the first half of their menstrual cycle)," Clue tells Bustle. "This increase in sweating was noticed not just on the face, but across the whole body." Why isn't fully known; it's probably tied to moderating body temperature so that you don't overheat.
2 Your Sweat Composition Changes During This Phase
While you're ovulating, the actual contents of your sweat may also change. A study in 2004 found that men could apparently subconsciously tell the difference between the sweat of ovulating and non-ovulating women — through smell alone. And, oddly, they rated the smell of the ovulating women's sweat to be the nicest. If you notice a different reaction to your deodorant during separate stages of your cycle, or if your partner says you smell different at various times of the month, you're likely not imagining things. (And yes, this does give you an excuse to sync your perfume with your menstrual phase.)
3 You May Have Night Sweats Thanks To Your Cycle
According to research in Scientific American in 2012, night sweats are only slightly more common among menopausal women than they are among healthy pre-menopausal women who still have periods. 22 percent of pre-menopausal women of all ages wake up in the night sweating, compared to 29 percent of menopausal women. And that appears to be tied to the hormone estradiol; asestradiol levels plummet in the body in the lead-up to menstruation, the likelihood of night sweats rises significantly. Estradiol levels are extremely low in menopausal women, hence their slightly higher propensity to get sweaty in the night.
4 You Sweat More During Exercise Before Your Period
In the luteal phase, after ovulation and before your period, your body's raised temperature also increases sweat during intense activity. In other words, you sweat more when exercising during this period. A 2006 study found that this was how women exercising on their luteal phase coped with the combination of intense activity and higher body temperature; they peed less and sweated more.
The ultimate lesson: don't be freaked out by shifts in your sweating levels throughout the month. They may just be tied to perfectly natural shifts in your hormones over the course of your menstrual cycle.