Comparative Pharmacology
Head-to-head clinical analysis: LEVORA 0 15 30 21 versus LEVORA 0 15 30 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVORA 0 15 30 21 versus LEVORA 0 15 30 28.
LEVORA 0.15/30-21 vs LEVORA 0.15/30-28
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 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.
One tablet orally once daily for 21 days, followed by 7 tablet-free days.
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).
None Documented
None Documented
20-30 hours for ethinyl estradiol; 2-4 hours for levonorgestrel. Steady-state reached in 5-7 days
Ethinyl estradiol: 13-27 hours (terminal); Levonorgestrel: 11-45 hours (terminal, dose-dependent due to SHBG binding).
Urine (50-60% as metabolites), feces (30-40% as glucuronides); <10% unchanged
Renal: ~50% (as glucuronide and sulfate conjugates of ethinyl estradiol and levonorgestrel); Fecal: ~50% (enterohepatic recirculation).
Category C
Category C
Oral Contraceptive
Oral Contraceptive