Cervical CapvsVaginal 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	Cervical Cap A small silicone cap that fits over the cervix by suction, used with spermicide before sex.	Vaginal pH Modulator A prescription gel used before sex that keeps vaginal pH acidic to disable sperm.
Efficacy	Least 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	$73–$97 Insurance: Usually	$0–$400 /per package Insurance: Usually
Duration	Reusable for 2 years (replace every 2 years or sooner if damaged)	Single use (effective for 1 hour)
Reversibility	Reversible	Reversible
STI Protection	No	No
How it works	A small silicone cap fits snugly over the cervix and stays in place by suction, blocking sperm from entering the uterus. Used with spermicide inside the cap.	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.
Prescription	Required Prescription required	Required Prescription required
Side effects	Vaginal irritation from spermicide Discomfort if not fitted correctly Unusual vaginal discharge if left in too long	Vaginal burning or irritation Increased risk of urinary tract infection Rare allergic reaction
Who shouldn't use this	Cervical anomaly preventing fit Active pelvic infection Sensitivity to silicone or spermicide Inability to insert or remove reliably	Recurrent UTIs or urinary tract abnormalities (FDA label says avoid use)

Key differences

Cervical Cap duration: Reusable for 2 years (replace every 2 years or sooner if damaged). Vaginal pH Modulator duration: Single use (effective for 1 hour). Cervical Cap: costs $73–$97. Vaginal pH Modulator: costs $0–$400 per package.