The biological effects of norgestrel alone and in combination with ethinyl oestradiol.

Workers at Wyeth Laboratories Inc. in Philadelphia have examined the biological properties of norgestrel ethinyl estradiol and their combination in the oral contraceptive Ovral (.5 mg norgestrel .05 mg ethinyl estradiol). The emphasis of their research has been however on the actions of norgestrel. In the first portion of the paper norgestrel is compared to other progestagens; its properties here are described irrespective of dosage or route of administration. The second part of the paper considers effects occurring upon administration of Ovral and its components at doses approximating 1- 5- and 25-fold multiples of the human dose on a body weight basis. Among the effects considered are progestational gonadotrophin block miscellaneous reproductive and adrenal corticoid effects.