Comparative Pharmacology
Head-to-head clinical analysis: LEVORA 0 15 30 21 versus MICROGESTIN 1 5 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVORA 0 15 30 21 versus MICROGESTIN 1 5 30.
LEVORA 0.15/30-21 vs MICROGESTIN 1.5/30
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on hypothalamic-pituitary axis; levonorgestrel inhibits ovulation and thickens cervical mucus, impairing sperm penetration. Also induces endometrial atrophy.
Combination oral contraceptive containing norethindrone acetate (progestin) and ethinyl estradiol (estrogen). Suppresses gonadotropin secretion (FSH, LH) via negative feedback on hypothalamic-pituitary axis, preventing ovulation. Also increases cervical mucus viscosity and alters endometrial receptivity.
One tablet orally once daily for 21 days, followed by 7 tablet-free days.
One tablet (norethindrone acetate 1.5 mg/ethinyl estradiol 30 mcg) orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
None Documented
None Documented
20-30 hours for ethinyl estradiol; 2-4 hours for levonorgestrel. Steady-state reached in 5-7 days
Norethindrone: 8-11 hours; Ethinyl estradiol: 13-19 hours. Steady-state reached within 5-7 days.
Urine (50-60% as metabolites), feces (30-40% as glucuronides); <10% unchanged
Renal: ~50-60% (primarily as glucuronide conjugates of ethinyl estradiol and norethindrone); Fecal: ~40-50% (via biliary elimination)
Category C
Category C
Oral Contraceptive
Oral Contraceptive