Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus ZOVIA 1 35E 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus ZOVIA 1 35E 28.
NORLESTRIN 28 1/50 vs ZOVIA 1/35E-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
ZOVIA 1/35E-28 is a combined oral contraceptive (COC) containing ethinyl estradiol and norethindrone. It inhibits ovulation via suppression of gonadotropins (FSH and LH), increases cervical mucus viscosity, and alters endometrial receptivity.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
One tablet orally once daily at the same time each day for 21 days, followed by 7 days of placebo (inactive tablets), then repeat.
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Ethinyl estradiol: ~17 hours (range 13-27 hours); Norethindrone: ~8 hours (range 5-14 hours). Clinical context: Steady state achieved in ~5-7 days; contraceptive effect requires consistent dosing.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Renal: ~40% as metabolites; biliary/fecal: ~40% as metabolites; unchanged drug minimal (<1%).
Category C
Category C
Oral Contraceptive
Oral Contraceptive