Comparative Pharmacology
Head-to-head clinical analysis: GILDESS 1 20 versus NORLESTRIN 28 1 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GILDESS 1 20 versus NORLESTRIN 28 1 50.
GILDESS 1/20 vs NORLESTRIN 28 1/50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
GILDESS 1/20 is a combination oral contraceptive containing ethinyl estradiol (an estrogen) and gestodene (a progestin). Its primary mechanism is inhibition of ovulation via suppression of gonadotropin-releasing hormone (GnRH), leading to reduced follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion. Additionally, it alters cervical mucus (increasing viscosity to impede sperm penetration) and endometrial structure (rendering it unsuitable for implantation).
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
One tablet orally daily, each containing 20 mcg ethinyl estradiol and 150 mcg desogestrel.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
None Documented
None Documented
Ethinylestradiol: terminal half-life ~13-27 hours (mean 17 hours). Gestodene: terminal half-life ~12-15 hours. Steady-state reached within 5-7 days.
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Renal (estradiol: ~40-50% as glucuronide and sulfate conjugates; gestodene: ~30-40% as metabolites) and fecal (estradiol: ~20-30%; gestodene: ~30-40%). Less than 1% excreted unchanged.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Category C
Category C
Oral Contraceptive
Oral Contraceptive