External CondomvsSpermicide

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	External Condom A non-hormonal barrier method that also lowers the risk of STIs, available over the counter.	Spermicide A chemical gel, foam, or film inserted into the vagina before sex to disable sperm, available over the counter.
Efficacy	87% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.	79% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.
Cost	$0.5–$3 /per unit Insurance: Varies	$1–$3 /per unit Insurance: Varies
Duration	Single use	Single use (effective for 1 hour; duration varies by formulation, check product label)
Reversibility	Reversible	Reversible
STI Protection	Yes	No
How it works	A physical sheath worn over the penis that blocks semen from entering the vagina and reduces skin-to-skin contact that transmits STIs.	A chemical (usually nonoxynol-9) immobilizes or kills sperm on contact. Inserted into the vagina before sex.
Prescription	OTC No prescription / OTC	OTC Over-the-counter
Side effects	Rare local irritation from latex or lubricants	Vaginal or penile irritation Increased risk of UTI Allergic reaction (rare)
Who shouldn't use this	Known allergy to latex (use polyisoprene or polyurethane instead)	Sensitivity to nonoxynol-9 Active vaginal irritation or infection High risk of HIV exposure (frequent use may increase transmission risk)

Key differences

External Condom is more effective (87% vs 79% typical use). External Condom duration: Single use. Spermicide duration: Single use (effective for 1 hour; duration varies by formulation, check product label). Only External Condom protects against STIs. External Condom: costs $0.5–$3 per unit. Spermicide: costs $1–$3 per unit.