Sponge
vs
Vaginal pH Modulator

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
Sponge

Sponge

A soft foam disc placed deep in the vagina before sex. It covers the cervix and contains spermicide.
Vaginal pH Modulator

Vaginal pH Modulator

A prescription gel used before sex that keeps vaginal pH acidic to disable sperm.
EfficacyLeast effective see details

Least effective: under 90 out of 100 people successfully prevent pregnancy per year.

86.3% typical use

Least effective: under 90 out of 100 people successfully prevent pregnancy per year.

Cost$15–$20 /per package

Insurance: No

$0–$400 /per package

Insurance: Usually

DurationSingle use (can be left in place up to 24 hours and for multiple acts of sex)Single use (effective for 1 hour)
ReversibilityReversibleReversible
STI ProtectionNoNo
How it works

A foam disc impregnated with spermicide is placed over the cervix before sex. The spermicide kills or disables sperm and the physical barrier blocks sperm from entering the uterus.

A gel containing lactic acid, citric acid, and potassium bitartrate maintains an acidic vaginal pH that disables sperm and reduces their motility. It also acts as a physical barrier to sperm movement.

PrescriptionOTC No prescription / OTCRequired Prescription required
Available Products1 product1 product
Side effects
  • Vaginal irritation or dryness
  • Increased risk of urinary tract infection
  • Rare allergic reaction
  • Vaginal burning or irritation
  • Increased risk of urinary tract infection
  • Rare allergic reaction
Who shouldn't use this
  • Allergy to nonoxynol-9, benzalkonium chloride, or other spermicide ingredients
  • History of toxic shock syndrome
  • Active vaginal infection
  • Inability to insert or remove reliably
  • High risk of HIV exposure (frequent nonoxynol-9 use may increase vaginal irritation; CDC cautions)
  • Active vaginal infection
  • Recurrent UTIs (use may increase risk)