Some estrogenic effects of two oral contraceptives consisting of norgestrel and two different doses of ethynylestradiol.

Some biological and biochemical effects (i.e. KPI, cervical mucus, SHBG and ceruloplasmin) as well as serum ethynylestradiol and serum norgestrel, following the use of two oral contraceptives containing the same amount of norgestrel (dl-norgestrel 0.5 mg) and either 30 microgram or 50 microgram of ethynylestradiol were compared. There was no difference in the clinical features in either group of patients. There was a statistically significant difference in the levels of unconjugated ethynylestradiol but not in the other biochemical parameters studied. It is concluded that the absence of any such difference might be attributable to the strong antiestrogenic effects of dl-norgestrel.