What effect does estrogen/progestin therapy have in women with an intact uterus who are treated with estrogen?

Estrogen therapy alone in women with an intact uterus can lead to an increased risk of endometrial hyperplasia, which can potentially progress to endometrial cancer. The addition of progestin to estrogen therapy is essential for women who have not undergone a hysterectomy, as progestin counteracts this risk. Progestin works by inducing a regular shedding of the endometrial lining, thereby reducing the likelihood of hyperplasia.

In this context, the combination therapy effectively protects the endometrium by maintaining a balanced hormonal environment, preventing excessive proliferation of the endometrial tissue. Thus, the statement that the therapy prevents endometrial hyperplasia is accurate, highlighting the critical role of progestin in mitigating the adverse effects associated with estrogen use in women with an intact uterus.