In some girls and women the pill (or COCP) does seem to help with management of acne, and may be a suitable treatment option. The pill reduces the amount of "androgens" (male sex hormones) circulating in the body. Androgens are present in the female body, and are known to be associated with acne, as they cause the skin to produce more "sebum" (oils), particularly during puberty- so the pill can be helpful by reducing this process. However, it is important to note that the "mini pill" or "progesterone only pill" does not reduce circulating androgens, thus does not appear to help acne. Also, different brands and formulations of the COCP exist, and different ones may be more effective than others, in different individuals. Your doctor can assist with selecting the best option for you. 

Some women find the pill doubly useful as a way to manage their contraception needs as well as their acne. 

To get a prescription for the contraceptive pill, start here.