Summary.
A new synthetic orally active progestational agent 'Medrogestone' was investigated and its activity compared to progesterone and medroxyprogesterone acetate (map). Medrogestone fulfils the criteria of a pure gestagen, it has a spectrum of biological activity similar to that of progesterone but unlike progesterone, it is orally active. Medrogestone is free of undesirable side effects in experimental animals. It is being investigated clinically as an oral progestin (Carter, Faucher & Greenblatt, 1964).