Comparative Pharmacology
Head-to-head clinical analysis: LO LOESTRIN FE versus LO OVRAL 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LO LOESTRIN FE versus LO OVRAL 28.
LO LOESTRIN FE vs LO/OVRAL-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol and norethindrone acetate suppresses gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary, thereby inhibiting ovulation. The progestin component thickens cervical mucus, impeding sperm penetration, and alters endometrial receptivity. Ferrous fumarate provides supplemental iron.
Combination of norgestrel, a progestin, and ethinyl estradiol, an estrogen; suppresses gonadotropin secretion (FSH and LH) primarily via progestational activity, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial development, reducing implantation likelihood.
One tablet orally once daily. Each tablet contains norethindrone acetate 1 mg and ethinyl estradiol 10 mcg (24 active tablets) followed by ferrous fumarate 75 mg (2 inactive tablets).
One tablet orally once daily for 28 days. Each tablet contains 0.3 mg norgestrel and 0.03 mg ethinyl estradiol. Active tablets (21 days) followed by placebo tablets (7 days).
None Documented
None Documented
Norethindrone: ~8 hours (range 5–12 h); Ethinyl estradiol: ~14 hours (range 10–20 h). Terminal half-life supports once-daily dosing with steady-state reached within 7–14 days.
Norgestrel: 20-40 hours; Ethinyl estradiol: 13-27 hours. Steady-state achieved after 3-5 half-lives.
Renal (primarily as glucuronide conjugates of norethindrone and ethinyl estradiol): ~40% norethindrone metabolites, ~30% ethinyl estradiol metabolites; Fecal: ~30% norethindrone metabolites, ~40% ethinyl estradiol metabolites.
Renal (approx. 50% as metabolites, <1% unchanged); biliary/fecal (approx. 50% as metabolites).
Category C
Category C
Combination Oral Contraceptive
Combination Oral Contraceptive