A new book from a Texas professor casts new light on the impact of the pill.
"This is Your Brain on Birth Control: The Surprising Science of Women, Hormones and the Law of Unintended Consequences" suggests that taking the birth control pill makes women have different versions of themselves.
Personal experience prompted psychology professor Sarah E. Hill, Ph.D. at Texas Christian University in Fort Worth to write the book. She took the birth control pill through college before stopping taking it to have children.
"And, after we had our second child, we decided to go for something for permanent," Hill said. "I went off the pill, and I felt like I woke up from a nap, like I felt like the world was a little brighter and more interesting, and I felt more vibrant and I had energy."
Hill, who is especially interested in women's health and women's relationships, wanted to know if there was a connection between the birth control pill and the brain.
"I was shocked to learn that in some cases, researchers have been studying this for decades and the different ways that it influences the structure of the brain, the function of the brain, the way that it influences who we're attracted to romantically," she said. "It can influence the quality of our relationships. It influences the stress response which is so far downstream from sex hormones that most people would never imagine that the pill would have an influence on these types of processes."
Her deep dive into decades of research compelled her to write a book and share the information with other women.
"You can't make a small change in the body and not have it influence everything else," she said.
Hill discovered the pill does more than prevent pregnancy.
One of her key revelations is that the pill changes the body's response to stress. There is no surge of the stress hormone cortisol in women who take the pill.
"We might all think if the stress response is shut down, it would be amazing. that it would be the best thing to ever happen to us because we all hate stress, but again, the experience of stress is caused by life not our stress hormones," Hill said. "So, what this really means for women is they may be actually less able to cope with stressors than non-pill taking women. And there's a lot of evidence to suggest this might be going on."
Her second big discovery was that being on the pill could influence who women choose as partners.
"When I first heard about this research, it was brain Velcro. I couldn't stop thinking about it 'cause it's so provocative," she said.
Again, decades of research by others pointed to startling conclusions.
"What they found was when women who chose their partner when they were on the pill, were in fact, more satisfied with things like their partner's financial provisioning and intelligence but they were less satisfied than the non-pill taking women," she said. "The naturally cycling women, they were more satisfied with the quality of their sex life, how sexually attracted they were to their partner, the amount of sexually chemistry. Anything with the word "sex" in it, the non-pill takers were reporting they were experiencing more of this with their partners relative to the ones who chose their partner when they were on the pill."
Hill says the information she uncovered and put in her book is not meant to alarm women but is rather additional information to "churn into the mill" when women are making decisions about their health.
She also hopes women use the information to push for more research.
"Women need to know that science historically has not been studying us," she said. "It's not because scientists are sexist. Women are more expensive. Hormones change cyclically. It slows down the pace of science."
The book doesn't give a "yes" or "no" answer to the question, "Should I take the pill?" But, she does hope the information puts women "in a position of power," she wrote.
"Really, what it comes down to is, the answer to that question is uniquely specific and it's going to depend on who she is, where she is in her life, and what her goals are," she said. "And, I think for a lot of women, given that this is the most easy to use, safe, effective mode of birth control out there right now, for a lot of women, it's still going to make sense at some point in her life, to be on the birth control pill. I think that when women are making this decision, there are some things they need to look out for."
Penguin Random House will release "This is Your Brain on Birth Control: The Surprising Science of Women, Hormones and the Law of Unintended Consequences" on Tuesday, Oct. 1.