Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN 1 20 versus OVRAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN 1 20 versus OVRAL.
MICROGESTIN 1/20 vs OVRAL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing estrogen (ethinyl estradiol) and progestin (norethindrone acetate). Inhibits gonadotropin secretion (FSH, LH) via negative feedback, preventing ovulation. Also causes cervical mucus thickening and endometrial thinning.
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 (norethindrone acetate 1 mg / ethinyl estradiol 20 mcg) orally once daily for 21 consecutive days, followed by 7 days of placebo or no tablets.
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: 5.2-12.8 hours (mean ~8 hours); Ethinyl estradiol: 7-20 hours (mean ~13 hours); hepatic impairment prolongs.
Norgestrel: 24–32 hours; Ethinyl estradiol: 12–18 hours; steady-state achieved after 5–7 days
Renal: 40% as metabolites, 20% as glucuronide and sulfate conjugates; Fecal: 35%; Biliary: <5%.
Renal (60% as metabolites, ~40% unchanged); biliary/fecal (40%)
Category C
Category C
Oral Contraceptive
Oral Contraceptive