Diaphragm
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 |  DiaphragmA reusable silicone dome that covers the cervix to block sperm, used with spermicide each time you have sex. |  Vaginal pH ModulatorA prescription gel used before sex that keeps vaginal pH acidic to disable sperm. |
|---|---|---|
| Efficacy | 83% typical use 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 | $80–$200 Insurance: Usually | $0–$400 /per package Insurance: Usually |
| Duration | Reusable for 1-2 years (replace every 1-2 years or sooner if damaged) | Single use (effective for 1 hour) |
| Reversibility | Reversible | Reversible |
| STI Protection | No | No |
| How it works | A reusable silicone dome covers the cervix to block sperm from entering the uterus. Used with spermicide for added effectiveness. | 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 |
| Available Products | 2 products | 1 product |
| Side effects |
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| Who shouldn't use this |
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