Comparative Pharmacology
Head-to-head clinical analysis: GENCEPT 10 11 21 versus LEVORA 0 15 30 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GENCEPT 10 11 21 versus LEVORA 0 15 30 28.
GENCEPT 10/11-21 vs LEVORA 0.15/30-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
GENCEPT 10/11-21 is a combination contraceptive vaginal ring containing ethinyl estradiol and etonogestrel. Ethinyl estradiol is an estrogen that suppresses gonadotropin release, inhibiting ovulation. Etonogestrel is a progestin that thickens cervical mucus, inhibiting sperm penetration, and alters the endometrium.
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 (10 mg ethinyl estradiol and 11 mg gestodene on days 1-7, then placebo on days 8-21) orally once daily for 21 days, followed by 7 placebo 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
Terminal elimination half-life is 24-30 hours; allows once-daily dosing; steady-state achieved in 5-7 days
Ethinyl estradiol: 13-27 hours (terminal); Levonorgestrel: 11-45 hours (terminal, dose-dependent due to SHBG binding).
Renal (30-40% as unchanged drug and metabolites), biliary/fecal (50-60% as metabolites)
Renal: ~50% (as glucuronide and sulfate conjugates of ethinyl estradiol and levonorgestrel); Fecal: ~50% (enterohepatic recirculation).
Category C
Category C
Oral Contraceptive
Oral Contraceptive