Plasma hormone levels in women receiving new oral contraceptives containing ethinyl estradiol plus levonorgestrel or desogestrel.

The changes in plasma hormone levels were evaluated in matched healthy female volunteers investigated before and after 6 months' use of three new oral contraceptives (OCs): TrigynonR (n = 13), a triphasic OC containing low doses of ethinylestradiol (EE) + levonorgestrel (LNg); MarvelonR (n = 14), a monophasic OC containing low doses of EE + desogestrel (DOG, a new progestogen derived from LNg); and OvidolR (n = 10), a sequential OC containing higher doses (50 micrograms) of EE + DOG. Serum levels of FSH, LH, estradiol and progesterone were decreased in all cases to levels incompatible with ovulation. Prolactin concentrations were unchanged. Sex hormone binding globulin (SHBG) and Transcortin (CBG) levels were significantly increased by all three OCs (Ovidol greater than Marvelon greater than Trigynon); free testosterone levels decreased significantly while free cortisol concentrations remained unchanged. Collectively, these data indicate that (a) all three OCs are effective ovulation inhibitors, (b) Ovidol and Marvelon have greater estrogenic effects than Trigynon, (c) LNg is more effective than DOG in reducing the EE-induced increase in SHBG levels, and (d) free testosterone levels are equally well suppressed by all three Ocs.