Transcortin as an indicator of estrogenic potency in oral contraceptives

Serum cortisol-binding globulin (CBG) was measured before, during and following a 21-day application period of 5 oral contraceptives used in the GDR. In a second group of patients determinations were carried out at the end of a 24-month treatment period and the end of the first post-treatment cycle. From a third group of volunteers blood samples were taken at the end of the first, second and third treatment cycles. All the drugs tested produced a marked increase of CBG in serum, reaching its maximum at the end of the second treatment cycle. Within four weeks following termination of application the level fell to the control range. There were no significant differences between the various contraceptives.