Tibolone, a tissue-selective compound with a combination of estrogenic, progestogenic and
androgenic properties, is used as an alternative for estrogen or estrogen plus progesterone
hormone therapy for the treatment of symptoms associated with menopause and osteoporosis. The
current study compares endometrial histology, biochemistry (hormone levels) and
gene-expression profiles after short-term (21-days) treatment with tibolone, to the findings
after treatment with estradiol-only (E2) and E2+Medroxyprogesterone Acetate (MPA) in healthy
postmenopausal women undergoing hysterectomy for endometrial prolaps.
Since short-term tibolone use results in increased spotting and bleeding but long-term
treatment with tibolone has been shown to lead to an atrophic endometrium our hypothesis is
that tibolone first displays a more estrogenic mode of action, which over time, is
counterbalanced by tibolone's progestagenic properties