"this is extremely effective in preventing pregnancy. however the side effects are horrible. i have been on my period for most of this year. i got this in around the end of february beginning of march about two weeks later i started a full on period. it lasted for about three months, my doctor had to give me a prescription for it to stop. then it stopped for about a month and started again and hasn&#039;t stopped since. that&#039;s another two months. i have been on my period for most of this year. this is not to mention the depression and 20 pound weight gain. "