By Molly Franzonello
When Dr. Sarah E. Hill first connected with Dr. Marguerite Duane, it was in the early days of the pandemic during a virtual seminar on hormones and mental health through Yale University. As a psychologist and evolutionary researcher, Dr. Hill was offering insights into the effects of hormonal birth control on the brain, while Dr. Duane presented clinical perspectives from the world of fertility awareness and restorative reproductive health care. Years later, that shared mission – to better understand the female body – has only deepened.
Now a featured speaker at the upcoming FACTS conference, Dr. Hill brings cutting-edge research and refreshing honesty about what we don’t know and what we need to do better.
From Personal Disruption to Professional Purpose
Dr. Hill holds a Ph.D. in evolutionary psychology, but her most defining work didn’t start in a lab. It started in her own body.
“I was on hormonal birth control for over a decade,” she said. “And when I came off, I felt like a completely different person. That personal experience sent me down a research rabbit hole to understand the effects of hormones on women’s psychology and behavior.”
While her graduate training had focused on human behavior and motivation broadly, Dr. Hill became increasingly frustrated by how male-centric most of the data was.
“The fields I was working in – motivation and health behaviors – were often studied exclusively from a male perspective. I wanted to understand how women uniquely experience the world,” she said.
That quest led her to become one of the most outspoken voices on the neurological and psychological effects of hormonal birth control, culminating in her bestselling book This Is Your Brain on Birth Control.
“The most surprising thing to me was how blind I had been,” she said. “Even as someone who deeply understood how sex hormones affect the brain, I had this enormous blind spot about the pill.”
Hormones Matter Everywhere
Dr. Hill’s central message is simple but profound: Hormones are not just about reproduction.
“They affect every system in the body: how we regulate stress, how we sleep, what we’re motivated to do, how we manage energy,” she said. “Estrogen and progesterone receptors are everywhere, from our bones to our brains, and yet we still treat these hormones as if they’re only relevant to getting pregnant or having a period.”
“Hormones affect every system in the body: how we regulate stress, how we sleep, what we’re motivated to do, how we manage energy.”
With menopause becoming a more visible cultural topic, Hill sees a hopeful shift: “As people begin to talk about the wide-ranging effects of hormone loss, we’re starting to see more curiosity about the role these hormones play throughout life, not just in fertility, but in mood, cognition, and long-term health.”
The XX Rules: Reframing the Female Body
To help women and clinicians reclaim this understanding, Dr. Hill developed a framework called “The XX Rules.” It’s a science-based approach to embracing the biological reality of being female.
“Our brains are wired differently,” she said. “They are sensitive to the constant hormonal fluctuations that come with having a menstrual cycle. And that’s not a flaw. It’s just a different system. But when women are trained to see themselves as ‘broken men,’ we end up designing systems – from work schedules to medical protocols – that ignore our reality.”
“Our brains are wired differently. They are sensitive to the constant hormonal fluctuations that come with having a menstrual cycle. And that’s not a flaw. It’s just a different system.”
From the air conditioning in office buildings to the default male-centered norms in clinical trials, she points to how structural design continues to leave women out.
“It’s not just about fairness; it’s about function,” Dr. Hill said. “Women deserve systems that are built with their biology in mind.”
Mentoring the Next Generation
For nearly two decades, Dr. Hill has served as a professor, researcher, and mentor. She currently oversees four Ph.D. students in her lab, where they explore how hormonal states shape behavior, cognition, and emotional regulation. Some of her current research projects aim to improve the experience of women on hormonal birth control by identifying interventions to mitigate negative side effects.
“We still don’t have great fertility regulation technology,” she said. “Many women feel stuck between a rock and a hard place. The goal is not to scare people away from birth control. It’s to make it better and give women more options.”
For her, mentoring young researchers is the most important part of her job.
“It’s how I shape the future of science,” Dr. Hill said. “And it’s how we move from recognizing the gaps to actually filling them.”
The Promise and Peril of Digital Health
Dr. Hill is also active in the digital health space, collaborating with companies like Mira, Flo Health, and 28 Wellness to bring science-backed insights into tech platforms for tracking hormones and cycles.
“There’s so much potential here,” she said. “Giving women real-time data about their bodies is incredibly empowering, but without proper education, that data can become overwhelming or misleading.”
“Giving women real-time data about their bodies is incredibly empowering, but without proper education, that data can become overwhelming or misleading.”
As a consultant, Dr. Hill plays dual roles: educator and researcher. She helps develop cycle phase-based user insights, conducts external evaluations on how app use impacts health literacy and body confidence, and supports efforts to align data tools with real scientific nuance.
Her core message to digital health leaders? Don’t just deliver data. Deliver understanding.
A Vision for the Future
When asked what she hopes her work will accomplish in the next 10 to 20 years, Dr. Hill doesn’t hesitate: “I want science and medicine to stop lumping women into male-based models of research. I want sex differences to be tested, reported, and respected. And I want women to be studied as hormonally dynamic beings – not just as afterthoughts.”
She envisions a world in which research includes not only women but women across all phases of their menstrual cycles, where results are stratified by hormonal state and progesterone-dominant phases are no longer ignored.
“Medicine is full of surprises for women because women haven’t been studied properly,” she said. “We need to stop asking why women’s bodies are reacting differently and start realizing we just never looked in the first place.”
It’s a call not just for better science, but for a more humane and accurate model of care. And with voices like Dr. Hill’s leading the way, the future looks not only more informed but finally designed with women in mind.
ABOUT THE AUTHOR
Molly Franzonello, RN, MHA, MS, DNP, is a midwife with a background in health care administration, health policy, and maternal health equity. Her professional goals include practicing full-scope midwifery care while continuing to write and publish on women’s health. She aims to integrate clinical practice, research, and advocacy to advance maternal and reproductive health through both direct patient care and systems-level change.
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