Comparative Pharmacology
Head-to-head clinical analysis: DEMULEN 1 35 21 versus NORINYL 1 50 28 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMULEN 1 35 21 versus NORINYL 1 50 28 DAY.
DEMULEN 1/35-21 vs NORINYL 1+50 28-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol (estrogen) and ethynodiol diacetate (progestin). Inhibits gonadotropin secretion (FSH, LH) via negative feedback on hypothalamic-pituitary axis, suppressing ovulation. Additionally, thickens cervical mucus and alters endometrial receptivity.
Norethindrone and ethinyl estradiol combination works by suppressing gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion, thereby inhibiting ovulation. Norethindrone also alters cervical mucus viscosity and endometrial lining, impeding sperm penetration and implantation.
One tablet orally once daily for 21 days, followed by 7 days off. Each tablet contains 1 mg ethynodiol diacetate and 35 mcg ethinyl estradiol.
One tablet orally once daily for 28 days, with 7 inactive tablets during the last 7 days. Each active tablet contains norethindrone 1 mg and ethinyl estradiol 50 mcg.
None Documented
None Documented
Ethinyl estradiol: 13±3 hours (terminal); norethindrone: 8±3 hours. Steady-state achieved after ~5 days.
Norethindrone: ~8-11 hours; Mestranol: 24 hours (prodrug, ethinyl estradiol half-life ~13-27 hours).
Renal (primarily as glucuronide and sulfate conjugates): ~60%; fecal: ~40%
Renal: ~40% as metabolites; Biliary/Fecal: ~60% as metabolites.
Category C
Category C
Oral Contraceptive
Oral Contraceptive