

That’s because both hormones, in different ways, typically support good sleep while estrogen works to keep body temperature low at night and helps regulate mood ( both things that can help you drift off more easily), progesterone can have a directly calming or sedating effect.

“It’s really in the last five days before bleeding that hormone levels are pretty low, and people tend to get sleep issues.” -Sara Nowakowski, PhD, sleep physician “Then, if you don’t get pregnant, those hormones start to drop,” she says, “so, it’s really in that second half of the cycle, and especially the last five days before bleeding-or what we call the late luteal phase-that hormone levels are pretty low, and people tend to get sleep issues.” In terms of the menstrual-cycle phases, the body typically sees a buildup of the hormones estrogen and progesterone during the follicular phase, or the part of the cycle that starts at menstruation and goes through the first two weeks, says clinical psychologist and sleep-medicine specialist Sara Nowakowski, PhD, whose research focuses on sleep in people who identify as women. Sleep problems before your period may stem from hormone fluctuations. Why the lead-up to menstruation can trigger sleep issues
