Comparative Pharmacology
Head-to-head clinical analysis: DEMULEN 1 50 21 versus LARIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMULEN 1 50 21 versus LARIN FE 1 20.
DEMULEN 1/50-21 vs LARIN FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
DEMULEN 1/50-21 is a combined oral contraceptive containing ethinyl estradiol and ethynodiol diacetate. Ethinyl estradiol and progestins inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation. Progestins also increase cervical mucus viscosity and alter endometrial receptivity, impeding sperm penetration and implantation.
LARIN FE 1/20 is a combination oral contraceptive containing ethinyl estradiol and norethindrone. It inhibits ovulation by suppressing gonadotropin release (FSH and LH) from the pituitary, increases viscosity of cervical mucus, and alters endometrial receptivity.
1 tablet (ethinyl estradiol 50 mcg, norethindrone 1 mg) orally once daily for 21 days, followed by 7 days off.
One tablet orally once daily for 21 consecutive days, followed by 7 days of placebo (ferrous fumarate) tablets per cycle.
None Documented
None Documented
Ethinylestradiol: 13 ± 3 h (biphasic; terminal phase used for dosing interval). Clinical context: steady-state achieved after ~3 days; missed dose may reduce contraceptive efficacy if >36 h.
Ethinyl estradiol: ~13 hours (range 7-20); norethindrone: ~8-11 hours. Steady-state reached in 5-7 days.
Renal (approx. 50% as metabolites, <1% unchanged), fecal (approx. 40%, largely as ethinylestradiol conjugates), biliary (minor, enterohepatic recirculation of ethinylestradiol)
Renal (60% as metabolites, <10% unchanged); biliary/fecal (40%)
Category C
Category C
Combination Oral Contraceptive
Combination Oral Contraceptive