How it Works

It is a synthetic form of progesterone that is given IM. It helps to suppress ovulation, possibly by inhibiting pituitary gonadotropin secretion, thus preventing follicular maturation and causing endometrial thinning.

Essentially, it tricks the body into believing it is constantly pregnant

Progesterone is secreted by the placenta and corpus luteum; providing the body with an exogenous form makes it believe it is producing it endogenously (ergo it thinks “hey I’m already pregnant”)