Its effects are mostly local, confined to the uterus, unlike the pills which act systemically. There's also Depo Provera
, which is a progesterone only (most pills have estrogen as well as progesterone) once every 3 months shot, and is quite effective if you get it on time. I don't know what it does to acne. There's also the implants, which go under your skin and last for several years.
You should talk to your gynecologist about switching.