Medroxyprogesterone
"I've been on depo for almost a year now. It's had its ups and down. Ups would be not having periods, no babies, and unprotected sex!!!!! Downs would be the red/brown spotting, weight gain and back pain (what I'm experiencing at the moment). The weight thing is a little weird. I usually weigh around 159-163, and I gained about 10 pounds and recently lost them from going to the gym and eating less fast foods. Overall, it's the best BC method. Keep in mind all that I described doesn't happen to all women, we all vary."