Comparative Pharmacology
Head-to-head clinical analysis: GILDESS 1 20 versus MICROGESTIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GILDESS 1 20 versus MICROGESTIN FE 1 20.
GILDESS 1/20 vs MICROGESTIN FE 1/20
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 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 orally daily, each containing 20 mcg ethinyl estradiol and 150 mcg desogestrel.
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
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: 5-14 hours (mean 8 hours); Ethinyl estradiol: 12-24 hours (mean 18 hours); Steady-state in 5-7 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.
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive