I don't know much about the drug but I do know about the condition. In 1992 I started having big pain during intercourse and sometimes even when I walked or was active. My doctor finally decided to go in and look after he tried a few things to alleviate my pain.
He did some surgery to clean it up and then put me on the pill for three months at a time to prevent regular monthly periods. I had already been on the pill for several years prior and this was just stepping up the use more than what I had done previously.
Needless to say, it did not help. I feel it got even worse. I suffered for 5 or 6 more years with constant pain and got to the point where tears would stream from my eyes when I was intimate with my husband no matter how careful he was. It just hurt.
In 2001 I decided to go off the pill and I got an IUD. First thing I noticed is that my very light, spotty three day periods went to 5 day heavy periods. It didn't really hurt more than my previous periods. It was just heavier and longer and I had less PMS believe it or not. After two or three months I noticed that my pain started to ease. The doctor just dismissed me and told me that my endometriosis would get worse because I was having heavy periods now. But it didn't. It got better. After every heavy period it really improved.
I decided to get pregnant the next year and had the IUD removed. I got pregnant five months later. I was pregnant for 10 months, nursed and did not have a period for 10 months, then had three or four periods and got pregnant again. I was again pregnant for 10 months, nursed and did not have a period for 10 months and then had about a years worth of periods.
I have had very little pain if any during all this time.
My personal opinion. It was being on the pill from the time I was 17 that caused it. The theory is that it is backflow. Well while on the pill I didn't bleed. My periods were so light and short that I could practically go the three days with one pad if it weren't so unsanitary. The only reason I changed was for hygeine reasons not because the bleeding.
I do believe that the lack of shedding was what caused my endo. When they put me on the pill for three months that made it even worse. Your body wants to get rid of that stuff. When it can't it just migrates, builds up and so on.
I could be wrong but from my experience having a heavy period and then being pregnant and not having one for so long is what cleared mine up.
I will have my third child at 40 in a few weeks. This will probably be my last so I'm curious to see if my symptoms will ever return. I won't go on the pill again. That's for sure...especially not at my age.
Any way, that is my very unscientific opinion and experiences.