Depo-Provera
"Have been on depo for about 9 years now and have No periods. When I first started depo I was bleeding for about a month til it just went away. 

Probably gained some weight, I feel the depo has me very moody and also makes me feel tired, it gives me lots of nervousness but surely prevents pregnancy, I'm not sure that it's safe to be on depo for a long time because it can cause weakness in bones, so consult your Dr on how long you should use it."