Steroids inhibiting ovulation.

produced by the corpus luteum of pregnancy, and later by the placenta, are responsible for this effect. Similarly, the administration of the naturally occurring steroids, such as estradiol and progesterone can inhibit ovulation. However, these steroids are unsatis factory for clinical use as they are not regularly effective and secondly, the parenteral administration of progesterone is painful. The male hormone, testosterone, can also inhibit ovulation but cannot be used routinely clinically because of androgenic side effects. Thus, a search of other steroid derivatives was undertaken in attempts to find a satisfactory compound for human use.