Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN 1 20 versus TRI LEGEST FE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN 1 20 versus TRI LEGEST FE.
MICROGESTIN 1/20 vs TRI-LEGEST FE
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.
Tri-Legest FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone acetate. It prevents ovulation by inhibiting gonadotropin release (FSH and LH) and alters cervical mucus and endometrial lining to impede 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 orally once daily for 28-day cycle: 21 days active tablets (norethindrone/ethinyl estradiol) followed by 7 days placebo. For contraception only.
None Documented
None Documented
Norethindrone: 5.2-12.8 hours (mean ~8 hours); Ethinyl estradiol: 7-20 hours (mean ~13 hours); hepatic impairment prolongs.
Norethindrone: 7-8 hours; Ethinyl estradiol: 18 hours (terminal). Steady-state reached after 7 days; clinical contraceptive efficacy requires consistent dosing.
Renal: 40% as metabolites, 20% as glucuronide and sulfate conjugates; Fecal: 35%; Biliary: <5%.
Renal: ~60% (metabolites), Fecal: ~30% (metabolites), Biliary: minor (~5% as conjugates)
Category C
Category C
Oral Contraceptive
Oral Contraceptive