Comparative Pharmacology
Head-to-head clinical analysis: NORINYL 1 80 28 DAY versus OVRAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORINYL 1 80 28 DAY versus OVRAL.
NORINYL 1+80 28-DAY vs OVRAL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing a progestin (norethindrone) and an estrogen (mestranol). Suppresses gonadotropin (FSH and LH) release via negative feedback, inhibiting ovulation. Also induces changes in cervical mucus and endometrium to impede sperm penetration and implantation.
OVRAL is a combination oral contraceptive containing ethinyl estradiol and norgestrel. It inhibits ovulation by suppressing gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus, reducing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) release from the pituitary. Additionally, it increases cervical mucus viscosity and alters endometrial receptivity, impeding sperm penetration and implantation.
One tablet (1 mg norethindrone / 80 mcg ethinyl estradiol) orally once daily for 28-day cycle without placebo.
One tablet (norgestrel 0.3 mg with ethinyl estradiol 0.03 mg) orally once daily for 21 days followed by 7 days of placebo.
None Documented
None Documented
Norethindrone: terminal elimination half-life of 5.3-10.5 hours; Mestranol (as ethinyl estradiol): terminal half-life of 7-20 hours. Clinically, steady state is achieved after 5-7 days of daily dosing; the half-life supports once-daily dosing for consistent hormonal levels.
Norgestrel: 24–32 hours; Ethinyl estradiol: 12–18 hours; steady-state achieved after 5–7 days
Norethindrone is primarily excreted in urine (approximately 60%) and feces (approximately 40%) as glucuronide and sulfate conjugates. Mestranol is metabolized to ethinyl estradiol; ethinyl estradiol and its metabolites are excreted in urine (40%) and feces (60%).
Renal (60% as metabolites, ~40% unchanged); biliary/fecal (40%)
Category C
Category C
Oral Contraceptive
Oral Contraceptive