Comparative Pharmacology
Head-to-head clinical analysis: LOW OGESTREL 21 versus MICROGESTIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LOW OGESTREL 21 versus MICROGESTIN FE 1 20.
LOW-OGESTREL-21 vs MICROGESTIN FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive. Suppresses gonadotropin release (FSH and LH) via estrogen (ethinyl estradiol) and progestin (norgestrel), inhibiting ovulation. Also increases cervical mucus viscosity and alters endometrium.
Combination oral contraceptive containing ethinyl estradiol (estrogen) and norethindrone acetate (progestin). Suppresses gonadotropins via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity and alters endometrial lining.
One tablet (norgestrel 0.3 mg/ethinyl estradiol 30 mcg) orally once daily for 21 days, followed by 7 pill-free days.
One tablet orally once daily, containing norethindrone acetate 1 mg and ethinyl estradiol 20 mcg, taken at the same time each day for 21 days followed by 7 days of placebo (iron tablets) or continuous cycling per prescribing information.
None Documented
None Documented
Norgestrel: 18-28 hours; ethinyl estradiol: 13-27 hours. Steady-state achieved after 5-7 days.
Norethindrone: 5-14 hours (mean 8 hours); Ethinyl estradiol: 12-24 hours (mean 18 hours); Steady-state in 5-7 days
Ethinyl estradiol and norgestrel are excreted primarily as glucuronide and sulfate conjugates in urine (50-60%) and feces (30-40%).
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive