"i am a teenage girl, and was told to go on the depo after my mother found out that i have been having sex with my boyfriend. i&#039;ve been on it since i was 15, and i never even had to worry. i haven&#039;t gotten my period since then, and i have only gained 10 pounds. slight irritability, increase in my breast size by two cups. keep in mind that the weight you gain is all body fat. i have an ample amount of stretch marks on my legs especially. if you do not care about the weight gain, this birth control is definitely for you."