Comparative Pharmacology
Head-to-head clinical analysis: FEMLYV versus NORINYL 1 80 21 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FEMLYV versus NORINYL 1 80 21 DAY.
FEMLYV vs NORINYL 1+80 21-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of levonorgestrel, a progestin, and ethinyl estradiol, an estrogen; suppresses gonadotropins, inhibits ovulation, alters cervical mucus and endometrium.
Combination oral contraceptive containing norethindrone (a progestin) and ethinyl estradiol (an estrogen). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial morphology.
FEMLYV (norethindrone acetate/ethinyl estradiol) is administered as one tablet (1 mg norethindrone acetate/20 mcg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo tablets. The dosing regimen is continuous cyclic.
One tablet orally once daily for 21 days, followed by 7 days of no active treatment.
None Documented
None Documented
Terminal elimination half-life is approximately 24-30 hours, supporting once-daily dosing in most patients.
Norethindrone: 8-11 hours; Mestranol: 12-24 hours (metabolized to ethinyl estradiol with half-life 20-27 hours). Steady-state after 5-7 days.
Primarily renal (approximately 60-70% as metabolites, less than 10% as unchanged drug); fecal excretion accounts for about 20-30%.
Renal (40-60% as metabolites), fecal (20-30%)
Category C
Category C
Oral Contraceptive
Oral Contraceptive