Etonogestrel
"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't stopped since. That'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. "