DON'T DO IT!!! I was only on the shot for one year and I developed deep vein thrombosis in my armpit. I actually had a pulmonary embolism as a result, but was FORTUNATE enough to survive!!! Although I was 44 when I started the shot, I was extremely healthy, fit and a non smoker. I am now having to take a blood thinner for almost one year to ensure I do not develop any more clots. Do not take this shot....Find an alternative method of birth control!!!