Ella is a prescription emergency contraceptive pill that prevents pregnancy for up to 120 hours (5 days) after unprotected sex. It contains a single dose of ulipristal acetate, which works by delaying ovulation. Among morning-after pills, ella is the most effective oral option available, outperforming over-the-counter alternatives like Plan B, particularly when taken more than three days after unprotected sex.
How Ella Works
Ella delays ovulation by blocking the hormonal surge your body uses to release an egg from the ovary. What makes it unique is that it can still suppress this process even when ovulation is imminent. Most emergency contraceptive pills lose effectiveness once that hormonal surge begins, but ella can intervene at a later stage in the cycle, which is a key reason it remains effective over a longer window.
Ella does not end an existing pregnancy. If a fertilized egg has already implanted, the pill has no effect.
How Ella Compares to Plan B
Within the first three days after unprotected sex, ella and Plan B (levonorgestrel) perform similarly. The real difference shows up between days three and five. Clinical trial data from two randomized studies found that ella was associated with roughly 40% fewer pregnancies overall compared to levonorgestrel, and this advantage grew as more time passed after intercourse.
Plan B is available over the counter and costs less, which makes it a practical first choice if you’re within that 72-hour window and can get it quickly. But if you’re closer to the four- or five-day mark, ella is the stronger option.
Effectiveness by Body Weight
Body weight affects how well emergency contraception works, and this is another area where ella has an advantage. For people with a BMI over 30, levonorgestrel-based pills like Plan B become significantly less reliable, with unintended pregnancy rates climbing to around 6%. Ella maintains a much lower failure rate in the same group, closer to 2.5%. If you weigh more than about 165 pounds or have a BMI above 30, ella is generally the recommended emergency contraceptive.
Side Effects
Most people tolerate ella well. The most commonly reported side effects in clinical trials were headache (18%), nausea (12%), and abdominal pain (12%). Other effects included menstrual cramps (7 to 13%), fatigue (6%), and dizziness (5%). These side effects are typically mild and resolve within a day or two.
Ella can also shift the timing of your next period. It may come a few days earlier or later than expected. If your period is more than a week late, a pregnancy test is a reasonable next step.
Who Should Not Take Ella
Ella is not recommended for people who are already pregnant, though it is not known to harm an existing pregnancy. People with severe liver disease should avoid it because the drug hasn’t been specifically studied in that group. The European Medicines Agency also advises against ella for people with severe asthma that requires oral steroid treatment, since the drug’s mechanism could theoretically interfere with how those steroids work.
Interaction With Hormonal Birth Control
This is an important detail that many people miss. Ella and hormonal birth control can interfere with each other. Because ella works by blocking progesterone receptors, taking it alongside progestin-containing contraceptives (the pill, patch, ring, or hormonal IUD) may reduce the effectiveness of both the emergency contraception and your regular method.
After taking ella, you should use a barrier method like condoms until your next period arrives. If you then want to restart or continue hormonal birth control, that’s fine once your period has come. Planning ahead here matters, because taking your regular birth control pill the next morning could undercut the very reason you took ella.
Breastfeeding
Older guidelines recommended pumping and discarding breast milk for 24 hours after taking ella. Current FDA labeling no longer includes that restriction. Breastfeeding does not need to be interrupted if you take ella, though some older pharmacy handouts may still carry the outdated advice.
How to Get Ella
Unlike Plan B, ella requires a prescription in the United States. You don’t necessarily need an in-person visit to get one. Several options exist for quick access:
- Telehealth apps: The Planned Parenthood Direct app offers prescriptions in most states. Online services like Nurx and PRJKT RUBY also prescribe and ship ella.
- Your doctor or nurse: Many providers will call in a prescription to your pharmacy over the phone without requiring an office visit.
- Local pharmacies: Once you have a prescription, most pharmacies carry ella or can order it quickly.
Because ella works for a full five days, the prescription requirement doesn’t carry the same urgency penalty it might seem to. You have more time to obtain it than you would with Plan B, where effectiveness drops sharply after 72 hours. That said, sooner is always better. Ella is most effective when taken as early as possible, even though it maintains meaningful protection through day five.
Cost
Ella typically costs between $40 and $90 without insurance. Most insurance plans and Medicaid cover it with no out-of-pocket cost when dispensed with a prescription. Telehealth consultations may add a small fee, though some services bundle the visit and the medication together. If cost is a barrier, Planned Parenthood health centers often provide emergency contraception on a sliding fee scale.