The clinical profile of Org OD 14 ((7 alpha,17 alpha)-17-hydroxy-7-methyl-19-norpregn-5 (10)-en-20-yn-3-one) is remarkable in that the compound demonstrates simultaneous weak oestrogenic, androgenic and progestational activity after oral administration to animals. It was therefore studied to evaluate its efficacy in the treatment of the climacteric syndrome. Clinical data demonstrating these combined hormonal effects are reviewed in this paper: Administration of 2.5 mg/day Org OD 14 suppressed gonadotrophins in post-menopausal women and inhibited ovulation in fertile women. In post-menopausal women virtually no endometrial proliferation was induced, only occasional, very slight proliferation being seen. Even after 2 yr of therapy no endometrial hyperplasia was observed. A weak stimulatory effect on the vaginal mucosa was apparent. In addition, Org OD 14 prevented post-menopausal bone loss and alleviated vasomotor climacteric symptoms effectively. It also had a beneficial effect on mood and libido. Org OD 14 was well tolerated. The incidence of side effects (changes in body weight, vaginal bleeding) was low and similar to that with placebo treatment. Extensive safety studies of up to 5 yr duration, including liver function tests and metabolic studies, indicated no untoward effects. It was concluded that Org OD 14 is an effective and safe new preparation for the treatment of climacteric patients.