So the depo-provera shot can stop periods, after sometime, how safe is this for a woman's body?

Safe: Depo Provera (medroxyprogesterone) thins the lining of the uterus in many women which leads to cessation of periods. Menstrual bleeding on hormonal bleeding is drug induced and if the lining does not build, which is frequent with Depo-Provera p, then menstrual bleeding lightens or stops. It is safe since there is no lining build up to shed.