Estrogen cream goes directly into the vagina, according to WebMD. Once in the vagina, the estrogen is slowly released into the body. Some of the common estrogen creams include Premarin, Estrasorb and Ogen.
The estrogen releases into the vaginal wall, and it helps rebuild the lining of the urethra and vagina by promoting the production of collagen, explains WebMD. Doctors recommend using estrogen cream daily for three weeks, then two times a week after that. When using estrogen cream, women may find that the external area of the vagina becomes dry, and in this case, it is advisable to use a small amount of estrogen cream there as well.