Comparative Pharmacology
Head-to-head clinical analysis: NORTREL 1 35 21 versus ZOVIA 1 35E 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORTREL 1 35 21 versus ZOVIA 1 35E 28.
NORTREL 1/35-21 vs ZOVIA 1/35E-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol (estrogen) and norethindrone (progestin) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and inducing endometrial changes that reduce implantation likelihood.
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 for 21 days, followed by 7 days off, then repeat.
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: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 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.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Renal: ~40% as metabolites; biliary/fecal: ~40% as metabolites; unchanged drug minimal (<1%).
Category C
Category C
Oral Contraceptive
Oral Contraceptive