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Diaphragm
vs
Spermicide

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
Diaphragm

Diaphragm

A reusable silicone dome that covers the cervix to block sperm, used with spermicide each time you have sex.

Spermicide

Spermicide

A chemical gel, foam, or film inserted into the vagina before sex to disable sperm, available over the counter.

Efficacy83% 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$80–$200

Insurance: Usually

$1–$3 /per unit

Insurance: Varies

DurationReusable for 1-2 years (replace every 1-2 years or sooner if damaged)Single use (effective for 1 hour; duration varies by formulation, check product label)
ReversibilityReversibleReversible
STI ProtectionNoNo
How it works

A reusable silicone dome covers the cervix to block sperm from entering the uterus. Used with spermicide for added effectiveness.

A chemical (usually nonoxynol-9) immobilizes or kills sperm on contact. Inserted into the vagina before sex.

PrescriptionRequired Prescription requiredOTC Over-the-counter
Available Products2 products2 products
Side effects
  • Increased risk of urinary tract infection
  • Vaginal irritation from spermicide
  • Discomfort if not fitted correctly
  • Vaginal or penile irritation
  • Increased risk of UTI
  • Allergic reaction (rare)
Who shouldn't use this
  • Uterine or cervical anomaly preventing fit
  • Sensitivity to silicone or spermicide
  • Inability to insert or remove reliably
  • Sensitivity to nonoxynol-9
  • Active vaginal irritation or infection
  • High risk of HIV exposure (frequent use may increase transmission risk)