Comparative Pharmacology
Head-to-head clinical analysis: LEVORA 0 15 30 28 versus MICROGESTIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVORA 0 15 30 28 versus MICROGESTIN FE 1 20.
LEVORA 0.15/30-28 vs MICROGESTIN FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation. Also induces changes in cervical mucus (increasing viscosity) and endometrium (reducing receptivity) to impair sperm penetration and implantation.
Combination oral contraceptive containing ethinyl estradiol (estrogen) and norethindrone acetate (progestin). Suppresses gonadotropins via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity and alters endometrial lining.
One tablet orally once daily at the same time each day for 28 days (21 active tablets containing 0.15 mg levonorgestrel and 0.03 mg ethinyl estradiol, followed by 7 placebo tablets).
One tablet orally once daily, containing norethindrone acetate 1 mg and ethinyl estradiol 20 mcg, taken at the same time each day for 21 days followed by 7 days of placebo (iron tablets) or continuous cycling per prescribing information.
None Documented
None Documented
Ethinyl estradiol: 13-27 hours (terminal); Levonorgestrel: 11-45 hours (terminal, dose-dependent due to SHBG binding).
Norethindrone: 5-14 hours (mean 8 hours); Ethinyl estradiol: 12-24 hours (mean 18 hours); Steady-state in 5-7 days
Renal: ~50% (as glucuronide and sulfate conjugates of ethinyl estradiol and levonorgestrel); Fecal: ~50% (enterohepatic recirculation).
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive