Dr. Tabatha Barber explains that combined/synthetic birth control pills work by shutting down hormonal communication between the brain and ovaries (the hypothalamic–pituitary–ovarian, HPO, axis) rather than 'regulating' hormones. She describes that long-term use can impair the brain–ovary signaling so that, after stopping the pill, many people experience absent, scant, or irregular periods; elevated androgens (notably testosterone); PCOS-like presentations; and potential impacts on fertility.
Chapters
So I really want you to know what you're signing up for. So birth control pills are synthetic hormones and they shut down the communication between your brain and your ovaries. So normally your brain and ovaries talk to each other by the hormones they produce. This is called the HPO axis, hypothalamic pituitary ovarian axis. And that communication is very important to keep your cycle balanced. The birth control pill does not regulate your hormones. That is a myth. It shuts down their production completely and overrides the system. What we have come to realize is that you're on this for 5, 10, 15 years and you try to come off of it. Sometimes the brain and the ovaries, they don't talk to each other when you come off of that pill because that system has been down for so long, they don't even know how to communicate. Often women will come off the birth control pill and not have a period, or they'll have just scant bleeding here and there, or it's super irregular. And what's happening is your brain and your ovaries don't know how to communicate properly. They don't know how to respond to each other. And so you're not getting a consistent regular cycle. Sometimes your androgens can be elevated, your testosterone particularly, and that can cause PCOS induced birth control. So a lot of issues are associated with long term birth control use. I'm seeing fertility infertility just rise because of this.
