Comparative Pharmacology
Head-to-head clinical analysis: CU 7 versus IMPLANON.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CU 7 versus IMPLANON.
CU-7 vs IMPLANON
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
The Cu-7 intrauterine device (IUD) releases copper ions, which inhibit sperm motility and viability, and alter the endometrial environment to prevent implantation.
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.
50 mg orally once daily
Insert 1 rod (68 mg etonogestrel) subdermally in the inner upper arm; replacement every 3 years.
None Documented
None Documented
Not applicable; intrauterine device with no systemic elimination half-life. Copper release is continuous with a rate of approximately 38 µg/day, declining over time.
Terminal elimination half-life is approximately 25-30 hours; significant interindividual variability
Primarily fecal (80-90%) as unabsorbed copper; negligible renal excretion (<1%).
Metabolites primarily excreted in urine (approximately 50%) and feces (30-35%)
Category C
Category C
Contraceptive
Contraceptive