Comparative Pharmacology
Head-to-head clinical analysis: LOW OGESTREL 21 versus MICROGESTIN 1 5 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LOW OGESTREL 21 versus MICROGESTIN 1 5 30.
LOW-OGESTREL-21 vs MICROGESTIN 1.5/30
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 norethindrone acetate (progestin) and ethinyl estradiol (estrogen). Suppresses gonadotropin secretion (FSH, LH) via negative feedback on hypothalamic-pituitary axis, preventing ovulation. Also increases cervical mucus viscosity and alters endometrial receptivity.
One tablet (norgestrel 0.3 mg/ethinyl estradiol 30 mcg) orally once daily for 21 days, followed by 7 pill-free days.
One tablet (norethindrone acetate 1.5 mg/ethinyl estradiol 30 mcg) orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
None Documented
None Documented
Norgestrel: 18-28 hours; ethinyl estradiol: 13-27 hours. Steady-state achieved after 5-7 days.
Norethindrone: 8-11 hours; Ethinyl estradiol: 13-19 hours. Steady-state reached within 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% (primarily as glucuronide conjugates of ethinyl estradiol and norethindrone); Fecal: ~40-50% (via biliary elimination)
Category C
Category C
Oral Contraceptive
Oral Contraceptive