Ella — also known as ulipristal acetate — is a morning-after pill. Taken orally within 120 hours of P-in-V sex, ella is designed to prevent sperm from fertilizing an egg. Meaning, it stops a pregnancy from ever occurring.
Emergency contraception like ella is designed to prevent pregnancy in anyone who is at risk of becoming pregnant but does not want to.
“If you were having intercourse and a condom popped, broke, or slipped off, the pregnancy risk is the same as it would be if you hadn’t used a condom at all,” explains Dr. Sophia Yen, CEO and co-founder of Pandia Health.
But how do you decide whether to use ella or another EC option?
Yen recommends that anyone who has decided to take an EC pill opt for ella.
“Ella has been proven to be a more effective emergency contraceptive pill than any other option when taken at any point within 5 days after sex,” she explains.
Ella contains a nonhormonal drug called ulipristal acetate.
This drug binds to the body’s progesterone receptors, which delays ovulation, explains Cristin Hackel, a nurse practitioner at Nurx.
She explains that it also decreases the endometrial thickness, which prevents a fertilized egg from attaching to the wall of the uterus (which is a necessary step in creating a pregnancy).
Ella has an efficacy rate of 85 percent when taken within 120 hours.
Yes, researchers recommend that people avoid the concomitant use of acid-suppressive drugs, such as proton pump inhibitors, histamine2-receptor antagonists, and antacids.
Hormonal birth control decreases effectiveness, too.
Before taking ella, talk with a healthcare professional to ensure it won’t interfere with your hormonal birth control, like the pill, patch, ring, or shot. Taking ella while on hormonal birth control can make them both less effective.
“Hormonal birth control contains progestin, and ella works by blocking the activity of progestin in the body, so if you take them together they may cancel each other out,” explains Hackel.
“After taking ella, use condoms for the rest of your cycle and resume your hormonal birth control after your next period,” says Hackel.
You can ella take up to 120 hours after sex. So as long as you take it within 120 hours, it should work!
That said, ella has been found to be most effective for those with a BMI of 30 or less. A single dose was found to be ineffective for people with a BMI of 35 or more.
(Plan B is most effective for those with a BMI of 25 or less, which makes ella accessible to a higher percentage of the population).
If you have a BMI over 30, doubling the dose of your EC pill may increase its effectiveness.
The most common side effect is a change in your next period.
However, there’s no way to know whether these changes result from the medication itself or the stress of being in a situation where you could get pregnant.
“Stress is a really common modulator of menstruation, so it’s hard to know if the menstrual changes are just a stress response,” says Yen.
It’s also common to notice more spotting before and after your period than usual, and for your blood flow to be altered.
Some people have also reported experiencing nausea, dizziness, or headache, notes Yen. But again, she says it’s unclear if that results from the medication or associated stress.
If you are prone to nausea, dizziness, or headaches, you might choose to preemptively take an OTC anti-nausea or anti-inflammatory medication.
“See a doctor right away if you experience severe pain in your lower stomach 3-5 weeks after using ella,” says Hackel. “As with any medication, get emergency care if you experience signs of an allergic reaction.”
Ultimately, it depends on whether or not you have insurance.
“Under the affordable care act, if you have insurance, any FDA-approved emergency contraception should be available for free,” says Yen. You can contact your health insurance provider, pharmacist, or doctor to find out if your plan covers ella.
If you’re not insured or you’re working with an in-person or telehealth provider that does not take insurance, ella typically costs between $50 and $60.
But these costs can vary — some places may charge over $100.
You may also be able to get ella for free or at a lower cost from your local health department, family planning clinic, or Planned Parenthood.
You’ll need to work with an in-person or telehealth provider to get a prescription.
A primary care physician, local health department, or family planning clinic can prescribe this medication.
If you’d prefer to use a telehealth provider, check out:
Once you have a prescription, you can purchase ella from an in-person pharmacy or online pharmacy.
Ella and Plan B are both safe, effective forms of emergency contraception. But understanding their key differences can help you determine which is best for you.
Ella contains ulipristal acetate and Plan B contains levonorgestrel.
Levonorgestrel is similar in function to a high dose of birth control pills. Like birth control, Plan B stops the ovaries from releasing eggs, while also preventing sperm from reaching and fertilizing any existing eggs.
Ella prevents or delays ovulation and makes it difficult for an egg to embed into the uterus.
“Ella can be taken for up to 5 days (120 hours) after unprotected sex, while Plan B and its generics can only be effective for up to 3 days,” says Hackel.
“This is because ella can prevent ovulation even once the pre-ovulation hormonal surge has begun, but Plan B can’t stop ovulation at that point.”
Research shows ella is at least 85 percent effective at this time, while Plan B is closer to 75 percent, depending on when you take it.
That said, “both medications are more likely to be effective if you take them as soon as possible after sex,” says Hackel.
Plan B is available OTC at your local pharmacy without a prescription. You need a prescription to purchase ella.
It ultimately depends on where in the post-sex timeline you’re at.
There’s no reason for you to take a pregnancy test right now. Most experts recommend waiting at least 2 weeks after sex to test.
Taking a test now will lead to a negative result because it’s simply too early to know.
You can take ella within 5 days of sex, so if you do want to avoid pregnancy, you’re still within the window to take it.
You should wait at least 2 weeks after sex without contraception or contraception failure to take a pregnancy test.
If it’s been longer than 14 days, go ahead and take a pregnancy test.
“If you have a positive pregnancy test, no emergency contraceptive will work,” says Yen. “There’s a totally different kind of pill, know as an abortion pill, that you’ll need to take to terminate the pregnancy.”
Have some other questions about ella? Below, a quick Q&A on this emergency contraceptive.
Nope. It’s prescription only.
If you want an OTC option, look into Plan B, Take Action, My Way, Option 2, Preventeza, AfterPill, My Choice, Aftera, and EContra instead.
(Just note that these options are going to be less effective for people with higher BMIs).
Most pharmacies carry ella, including Walgreens, CVS, and Target. Of course, there’s no harm in calling ahead of time to double-check.
“Ella is most likely to be effective if you take it before ovulation, so take it as soon as possible after sex,” says Hackel.
That isn’t to say that it won’t work if you take it after ovulating (but within 5 days of sex); it just may not be as effective.
If you’re looking for an EC method that’s just as effective after ovulation as it is before, consider getting a copper IUD, suggests Yen.
Yep! There are many other EC pills, and none require a prescription.
To be clear: This is an either/or situation.
You shouldn’t take ella at the same time as another EC pill, or within 5 days of another EC pill, because they could counteract each other and become ineffective.
It depends on what type!
Ella can only be taken once per menstrual cycle.
Levonorgestrel-based EC pills can, in theory, be taken multiple times during a cycle if needed. They aren’t associated with any long-term side effects or complications.
That said, if you find yourself regularly using EC, consider a hormonal or non-hormonal birth control option, which is more effective at preventing unwanted pregnancy than taking EC.
“After taking ella, about one third of people have no change in their next menstrual cycle, about one third of people report that their next period is early, and about one third report that it’s late,” explains Yen.
If you have sex without contraception or experience contraceptive failure and want to prevent pregnancy, several EC pills are available.
Ella is a safe, effective form of EC. It’s been proven to prevent pregnancy when taken within 5 days of sex. If you’re considering taking ella, talk with a healthcare professional to learn more.
Gabrielle Kassel is a New York-based sex and wellness writer and CrossFit Level 1 Trainer. She’s become a morning person, tested over 200 vibrators, and eaten, drunk, and brushed with charcoal — all in the name of journalism. In her free time, she can be found reading self-help books and romance novels, bench-pressing, or pole dancing. Follow her on Instagram.
Last medically reviewed on July 25, 2022
Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.
If you've had unprotected sex or experienced condom failure, there are a number of things you can do to prevent pregnancy and protect against STIs and…
Read on for steps you can take to help protect yourself, your partners, and your communities against unintended pregnancy and preserve access to…
We break down your options for birth control and how to get them, plus where to get free or lower-cost birth control in all 50 states and Washington…
Oral contraception is a safe, effective way to prevent pregnancy and relieve period pain. Here are the best online birth control delivery companies.
For people looking for a natural birth control method, Daysy is a good option. It’s easy to use and free of side effects. Here's all you need to know.
Antiprogestins mainly block the hormone progesterone, which makes them useful for early-stage abortions and emergency contraceptives.