Comparative Pharmacology
Head-to-head clinical analysis: NORTREL 1 35 21 versus ZOVIA 1 35E 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORTREL 1 35 21 versus ZOVIA 1 35E 21.
NORTREL 1/35-21 vs ZOVIA 1/35E-21
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.
Combination estrogen-progestin contraceptive; suppresses gonadotropin release, inhibits ovulation, alters cervical mucus and endometrial lining.
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 placebo tablets (if included in the pack) or a 7-day pill-free interval. Each tablet contains ethinyl estradiol 0.035 mg and norethindrone 1 mg.
None Documented
None Documented
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Norethindrone: 5-12 hours (terminal elimination half-life, approximately 8 hours). Ethinyl estradiol: biphasic with terminal half-life of 10-20 hours (mean 15 hours). Clinical context: Steady state reached in 5-7 days.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Renal (approximately 40% as parent drug and metabolites; 20-40% as metabolites; 15-20% as unchanged drug), fecal (30-50% via bile as metabolites), and less than 2% in breast milk.
Category C
Category C
Oral Contraceptive
Oral Contraceptive