THE PROGESTATIONAL ACTIVITY OF 17-α-ETHINYL-19-NORTESTOSTERONE*

Abstract

A new steroid. 17-a-ethinyl-19-nortestosterone (norethisterone), is an orally effective progesterone-like sub-stance because: (a) it induces secretory changes in the endo-metrium, (b) it can induce luteal changes in the vaginal cells, (c) it inhibits the phenomenon of arborization in cervical mucus, (d) it, like progesterone, induces a rise in basal temperature, and (e) it induces withdrawal bleeding in amenorrheic patients. Judging from the minimal doses required to induce withdrawal bleeding, norethisterone has a progestational activity about twice that of ethisterone. Norethisterone is not excreted as pregnane-diol. In general, no significant changes occurred in urinary 17-ketosteroid and 17-hydroxycorticoid excretion during administration of the drug.