Emergency Contraception Effectiveness Calculator

Effectiveness numbers express how often a medication prevents pregnancy in studies of people who use it correctly within the indicated window. They are not a personal guarantee, and they don't capture individual factors like body weight, current medications, or how close to ovulation you are when you take the pill.

For most people in most situations, the headline numbers are still the most useful summary because they reflect real-world outcomes across thousands of patients. But there are a few cases where the standard percentages can shift. Higher body weight reduces levonorgestrel's effectiveness more than ulipristal acetate's. Certain enzyme-inducing medications (rifampicin, some anti-epileptics, St. John's wort) can reduce effectiveness across both products. If you're unsure whether any of these factors apply to you, a Ruth Health clinician can review your situation before you order.

The calculator is intended as a decision aid, not a substitute for medical advice. Use it to make a more informed choice between Postinor and Mifestad, and reach out to support if your situation involves anything the standard numbers don't cover cleanly.

Once the calculator points you to a product, the fastest next step is to place the order through Ruth Health. In Metro Manila, same-day Lalamove delivery typically arrives within 40 minutes to two hours of dispatch. Outside the metro, J&T Express handles provincial shipments in one to four business days, which is one of the reasons Mifestad is recommended for most non-Metro orders — its longer effective window covers the time the package is in transit.

The intake form is short and designed to be filled out on a phone in a couple of minutes. If your situation includes any factors that need clinician input — uncertain timing, medications, breastfeeding, higher body weight — those questions are flagged for review before dispatch. The clinician confirms the right product (sometimes upgrading to Mifestad even when you initially selected Postinor) and the order ships from there.

If you'd rather pick up at a pharmacy, that's a valid option too. Postinor is available over the counter in most major Philippine pharmacy chains. Mifestad usually requires a prescription, which a Ruth Health clinician can issue if you'd prefer pharmacy fulfilment. Support can talk through the trade-offs if you're undecided.