Copper IUDvsExternal Condom

A side-by-side comparison of two birth control methods — efficacy, cost, how they work, and who shouldn't use them.

Side-by-side comparison

Method	Copper IUD A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.	External Condom A non-hormonal barrier method that also lowers the risk of STIs, available over the counter.
Efficacy	99.2% typical use Most effective: over 99 out of 100 people successfully prevent pregnancy per year.	87% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.
Cost	$0–$1,424 Insurance: Usually	$0.5–$3 /per unit Insurance: Varies
Duration	Up to 10 years	Single use
Reversibility	Reversible	Reversible
STI Protection	No	Yes
How it works	Releases copper ions into the uterus that make the environment toxic to sperm and may prevent implantation if fertilization occurs.	A physical sheath worn over the penis that blocks semen from entering the vagina and reduces skin-to-skin contact that transmits STIs.
Prescription	Required Prescription required	OTC No prescription / OTC
Side effects	Heavier or longer periods (especially first few months) Increased cramping Spotting between periods Small risk of uterine perforation at insertion	Rare local irritation from latex or lubricants
Who shouldn't use this	Active pelvic infection or PID (FDA label) Uterine anomaly preventing insertion (FDA label) Wilson's disease (copper metabolism disorder) (FDA label) Known copper allergy (FDA label) Current pregnancy (FDA label)	Known allergy to latex (use polyisoprene or polyurethane instead)

Key differences

Copper IUD is more effective (99.2% vs 87% typical use). Copper IUD duration: Up to 10 years. External Condom duration: Single use. Only External Condom protects against STIs. Copper IUD requires a prescription; External Condom does not. Copper IUD: costs $0–$1,424. External Condom: costs $0.5–$3 per unit.