Dear Dr. Kate,
I want to go on birth control but I get frequent migraines with aura. My neurologist suggested trying the progesterone-only pill but my gyno said its only 90% effective. I did some further investigating and read that it is actually 97% effective. Which is right? Also, will being on the POP give me the same benefits as pills that contain estrogen such as predictability, less cramping, and a lighter flow?
Your neurologist is right to advise you against birth control methods that don't contain estrogen (most pills, the patch and the ring). Women who have migraines with aura (visual or auditory symptoms that precede their headaches) have an increased risk of stroke if they're on an estrogen-containing method of contraception. But for most women with "common" migraines (no aura funny business), these methods are all fine.
Progesterone-only pills are about as effective as "combination" pills, but there's a catch. You need to take them at the same time every day. Taking a pill three hours late is like not taking it at all. I know, most of you pill takers have heard the same things about your "regular" birth control pills. But the truth is that estrogen-containing pills are a lot more forgiving, and the timing isn't as crucial. I think doctors still advise the same-daily-time for the sake of developing good pill-taking habits...but it's not related to how well the pill works.
So taking the POP pills at the same time daily give you the same level of protection against pregnancy. They'll also give you lighter periods and fewer cramps. Unfortunately, they don't give you the same kind of bleeding predictability as combination pills. You may get monthly periods...you may bleed irregularly throughout the month...and you may not get periods at all. The only way to know for sure is to try them out.
Have any of you tried the progesterone-only pill (Micronor)?