birth control
"I've had this implant since July 2014 and now I'm comfortable weighing in on it.  I'm 26, 5'2", 125 lbs on average.  I experienced mood swings only during the firsy two weeks after having implanted.  I had about three monthly periods that got consecutively lighter until I didn't have and now still don't have periods at all.  I'm regularly active and this hasn't effected my workouts at all."