Comparative Pharmacology
Head-to-head clinical analysis: ANNOVERA versus IMPLANON.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ANNOVERA versus IMPLANON.
ANNOVERA vs IMPLANON
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination hormonal contraceptive containing segesterone acetate, a progestin, and ethinyl estradiol, an estrogen. Segesterone acetate suppresses gonadotropin release, preventing ovulation; ethinyl estradiol contributes to contraceptive efficacy by stabilizing the endometrium and inhibiting gonadotropin secretion.
Etonogestrel, a progestin, binds to progesterone and androgen receptors, suppressing gonadotropin release (FSH, LH) and preventing ovulation. It also increases cervical mucus viscosity, impeding sperm penetration, and alters endometrial morphology.
One vaginal ring inserted and left in place for 3 weeks, followed by a 1-week ring-free interval. Each ring releases ethinyl estradiol 0.024 mg/day and segesterone acetate 0.15 mg/day over 21 days.
Insert 1 rod (68 mg etonogestrel) subdermally in the inner upper arm; replacement every 3 years.
None Documented
None Documented
Terminal half-life of etonogestrel (ENG): ~25 hours; ethinylestradiol (EE): ~12 hours; steady-state achieved after 7-14 days.
Terminal elimination half-life is approximately 25-30 hours; significant interindividual variability
Renal: ~60% as metabolites; fecal: ~35% as metabolites; biliary: minor.
Metabolites primarily excreted in urine (approximately 50%) and feces (30-35%)
Category C
Category C
Contraceptive
Contraceptive