This was incredibly informative, and made me feel hopeful that research related to birth control and those that use it is becoming more of a going concern. I learned a lot reading this, but was also left curious about where the research stands now, and wondering if most of society is even ready to have the complex conversation this book starts. I'm going to be sitting with this one for a while. Highly recommend reading this if you use hormonal birth control or are planning to start it.
My main issues with the book were things I kind of expected out of this--gender essentialism (which, again, to be expected, but there are points where it's quite excessive), more speculation on the meaning of certain research than is warranted (e.g., "not having women who are ovulating around them is leading to men becoming less ambitious" with very thin/nonexistent research to support it), and a tone I found a little condescending and didactic. I would contrast this with Come As You Are, a book also focused on cis women's sexual health (though focused on a different set of issues), which I feel has a warmer, more genuine friendly tone vs this book's more contrived one.
Even with these issues, though, it's absolutely worth reading.