It is well-known that PMS symptoms can deeply affect how women are feeling, including their mood, pain, and energy levels. But why exactly does this happen? Today, we’re going to dive into the science of sex hormones and the menstrual cycle, including how hormone levels affect women’s sexual motivation and tips for navigating sex at different phases of the cycle. I am joined by Dr. Sarah Hill, the author of This is Your Brain on Birth Control. She has spent most of her 20+ year career studying women, relationships, and health. Her latest book is titled The Period Brain: The New Science of Why We PMS and How To Fix It. Some of the specific topics we explore include: What’s the deal with PMS? Why did women evolve to feel like crap for half of the menstrual cycle? How do the rise and fall of different hormones during the cycle affect women’s brains? Progesterone is a hormone that’s supposed to make us feel good. So why doesn’t it have that effect during the second half of the menstrual cycle? How do estrogen and progesterone affect sexual motivation and desire? You can check our Sarah’s website to learn more about her work. Got a sex question? Send me a podcast voicemail to have it answered on a future episode at speakpipe.com/sexandpsychology. *** Thank you to our sponsors!  Expand your sexual horizons with Beducated! Featuring more than 100 online courses taught by the experts, Beducated brings pleasure-based sex ed directly into your bedroom. Enjoy a free trial today and get 50% off their yearly pass by using LEHMILLER as the coupon code. To redeem this offer, visit: https://beducate.me/lehmiller-sept Head to https://paired.com/JUSTIN and download the #1 app for couples to start maintaining your lasting love today. The Kinsey Institute at Indiana University has been a trusted source for scientific knowledge and research on critical issues in sexuality, gender, and reproduction for over 75 years. Be sure to register for the Sex and Aging Symposium, which will take place on October 4, 2025. *** Want to learn more about Sex and Psychology? Click here for previous articles or follow the blog on Facebook, Twitter, or Bluesky to receive updates. You can also follow Dr. Lehmiller on YouTube and Instagram. Listen and stream all episodes on Apple, Spotify, or Amazon. Subscribe to automatically receive new episodes and please rate and review the podcast! Credits: Precision Podcasting (Podcast editing) and Shutterstock/Florian (Music). Image created with Canva; photos used with permission of guest.