Tibolone is a synthetic steroid molecule which is, in essence, a progestogen. Post absorption, its metabolites have oestrogenic, progestogenic and androgenic properties (1, 2). The oestrogenic effects are exerted mainly in brain, bone and vaginal tissues and are responsible for control of vasomotor symptoms and prevention of bone loss. The effect of the progestogenic metabolites on the endometrium prevents hyperplasia.