The Period Brain

The New Science of Why We PMS and How to Fix It: A Manifesto for Women

De: Sarah E. Hill Ph.D.

Discover the empowering truth about your body from Dr. Sarah E. Hill, the leading researcher on women’s hormones. Part science and part feminist guide, this essential book demystifies the hormonal cycle, PMS, and PMDD, and advocates for a new understanding of women’s health.

Do you ever wish you could skip the week or two leading up to your period? You aren’t alone—most women feel like they are riding a horrible premenstrual roller coaster every month that leaves them feeling emotional, bloated, tired, anxious, and even unsexy.

Dr. Sarah E. Hill, an award-winning researcher who has spent two decades studying women’s psychology and health, explains why we feel so universally icky before our periods and—more importantly—what to do about it. The problem isn’t that women are hormonal; the problem is that the second half of the menstrual cycle—the luteal phase, when the hormone progesterone rises and estrogen decreases—has been systematically excluded by science. Progesterone is at the heart of every feeling we associate with PMS: it affects our daily sleep and calorie needs (hello, cravings!); whom we’re attracted to; our sex drive; and—as every woman can attest—our mood.

Because the luteal phase is understudied, every bit of health, diet, relationship, and exercise advice you’ve followed is based on that first, estrogen-glow half of the month or, worse, was designed for men. The rules that work for us in the first two weeks of the cycle don’t always fit in the second, causing most of us to spend half the month following advice that is completely at odds with the way our bodies work at this time. It’s no wonder we feel awful!

The Period Brain is a science-tested roadmap to understanding PMS and PMDD, and your ultimate guide to having a better period by making shifts to the way you eat, sleep, exercise, and socialize in the luteal phase. Discover how to take better care of yourself and your body, no matter when your period is due.

©2025 Sarah E. Hill, Ph.D (P)2025 HarperCollins Publishers