Comparative Pharmacology
Head-to-head clinical analysis: TRI LEGEST 21 versus ZOVIA 1 35E 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRI LEGEST 21 versus ZOVIA 1 35E 28.
TRI-LEGEST 21 vs ZOVIA 1/35E-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH), inhibits ovulation, alters cervical mucus and endometrium.
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 tablet-free days. Each tablet contains norgestimate 0.18 mg/ethinyl estradiol 0.025 mg (days 1-7), norgestimate 0.215 mg/ethinyl estradiol 0.025 mg (days 8-14), norgestimate 0.25 mg/ethinyl estradiol 0.025 mg (days 15-21).
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
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norgestimate active metabolite (norelgestromin): 22-36 hours (mean ~28 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.
Renal: approximately 50-60% as metabolites; fecal: approximately 40-50% (ethinyl estradiol and norgestimate metabolites excreted in bile and feces); less than 1% unchanged in urine.
Renal: ~40% as metabolites; biliary/fecal: ~40% as metabolites; unchanged drug minimal (<1%).
Category C
Category C
Oral Contraceptive
Oral Contraceptive