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Ella vs. Plan B for Emergency Contraception

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMPStacia Woodcock, PharmD
Updated on September 7, 2023

Key takeaways:

  • Emergency contraceptive pills are a safe and effective way to help prevent pregnancy after unprotected sex.

  • Ella (ulipristal) and Plan B (levonorgestrel) are two types of emergency contraceptive pills available. They have key differences, including how to access them, how soon after sex you should take them, and how often you can take them.

  • There are many ways to save on ella and Plan B. GoodRx can help make your medication more affordable. Patient assistance programs are also available.

Access savings on related medications

A person taking a pill in bed.
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If you’ve recently had unprotected sex, you may be looking for emergency contraception. Emergency contraception is a form of birth control that can help prevent a pregnancy from happening. It’s not a form of abortion and doesn’t stop an ongoing pregnancy.

There are a few emergency contraception options. One option is an intrauterine device (IUD) that’s placed by a healthcare provider in their office. Other options include pills you take by mouth. Two popular emergency contraception pills are ella (ulipristal) and Plan B One-Step (levonorgestrel).

If you’ve decided a pill is your preferred emergency contraception option, this article is for you. Here, we’ll discuss the differences between ella and Plan B.

Ella vs. Plan B in a nutshell

Ella and Plan B are both safe and effective options to prevent pregnancy. But there’s a few differences between them to consider.

An infographic comparing Plan B vs. Ella

What is Plan B?

Plan B contains levonorgestrel. It has multiple generic versions sold under a variety of brand names, such as Next Choice One Dose. It’s available over-the-counter (OTC) without age restrictions. This means that anyone of any age can buy Plan B.

You should take Plan B within 72 hours (3 days) of unprotected sex. But the sooner you take it, the more effective it will be. “Unprotected sex” could mean that you didn’t use any form of birth control. But it could also mean your birth control method failed, like if a condom broke or you forgot to take your birth control pills.

What is ella?

Ella contains the medication ulipristal. It’s only available as a brand-name medication and requires a prescription to purchase. Ella is most effective if you take it within 120 hours (5 days) of unprotected sex. But as with Plan B, the sooner you take ella, the better it will work.

How do ella and Plan B work for emergency contraception?

Plan B is a type of progestin (a lab-made version of the hormone progesterone). It prevents or delays ovulation. Ovulation is when an egg is released from the ovaries during the menstrual cycle. An egg must be present for you to become pregnant. If ovulation doesn’t happen, there’s no egg available to be fertilized by sperm.

By delaying or preventing ovulation, Plan B lowers the risk of pregnancy. Plan B does not cause an abortion. It won’t stop or harm a pregnancy that’s already happening.

Ella is a progestin agonist / antagonist. Like Plan B, ella works by preventing or delaying ovulation. But ella can also thin the lining of the uterus. This means that even if an egg is fertilized, ella makes it harder for it to implant and start a pregnancy.

Like Plan B, ella isn’t an abortion pill. But if you believe you’re already pregnant, you shouldn’t take ella. While ella won’t stop a pregnancy, there’s concern that taking ella during pregnancy could harm a developing fetus.

How do you take Plan B and ella?

Plan B is a single tablet that contains 1.5 mg of levonorgestrel. This one-time tablet should be taken as soon as possible after sex. You can start or continue other hormonal birth control methods right after taking Plan B.

You can take Plan B multiple times during each menstrual cycle if you need it. However, if you find yourself taking Plan B often, you should discuss other birth control options with your healthcare provider or local reproductive health center. Plan B isn’t a substitute for regular birth control.

Ella is also a one-time tablet taken immediately upon purchase. It contains 30 mg of ulipristal. Unlike Plan B, you should only take ella once per menstrual cycle. You also can't start or continue hormonal birth control for 5 days after taking ella.

How effective are Plan B and ella for emergency contraception?

When taken as directed, ella and Plan B are both very effective at preventing pregnancy. As mentioned above, they’re more effective the sooner they’re taken.

In studies, ella has been shown to be slightly more effective than Plan B when taken within 3 days. For people that took ella after unprotected sex, a little over 1% of them got pregnant. Of those that took Plan B, about 2% got pregnant.

You may have heard that, in a pinch, Plan B can be used for up to 5 days after unprotected sex. While this is better than nothing if you have no other options available, it’s not ideal. Ella is more effective than Plan B between 3 and 5 days after unprotected sex.

Some studies have found that Plan B may not work as well if you weigh more than 165 lbs. If you weigh more than 165 lbs, ella is considered the more effective pill for emergency contraception. Ella may be less effective if you weigh more than 195 lbs. But you can still take either ella or Plan B if needed, regardless of your body weight.

Keep in mind that how soon you take an emergency contraception pill is still the most important factor when it comes to how well they work. You can also discuss the copper IUD with your healthcare provider. This emergency contraceptive isn’t affected by body weight.

What are the common side effects of Plan B and ella?

Side effects of Plan B and ella are similar. The side effects are also similar to some of those caused by birth control pills. Usually, the side effects are mild and resolve quickly.

Common side effects of ella and Plan B, along with the percentage of people who experienced them in clinical trials, are detailed in the table below.

Side effect Plan B ella
Heavier periods 31% Not listed
Nausea 14% 12-13%
Abdominal pain 13% 8-15%
Fatigue 13% 6%
Headache 10% 18-19%
Dizziness 10% 5%
Breast tenderness 8% Not listed
Next period late by more than 7 days 5% 19%
Next period early by more than 7 days Not listed 7%
Breakthrough bleeding Possible, no percentage provided by manufacturer 9%
Menstrual cramps Not listed 7-13%

Taking ella or Plan B with food can help lessen or prevent stomach upset. If you throw up within 2 hours of taking Plan B or 3 hours of taking ella, contact your healthcare provider. You may need to take a second dose.

Can Plan B or ella affect future fertility?

Some people worry that emergency contraception pills may affect their future fertility. This isn’t true.

Using Plan B or ella doesn’t change your ability to get pregnant in the future. In fact, it’s possible to get pregnant shortly after taking emergency contraception pills. Because of this, it’s best to use a regular form of birth control after taking either Plan B or ella.

What interactions do Plan B and ella have?

You shouldn’t start or continue other hormonal birth control within 5 days of taking ella. Ella can cause other forms of hormonal birth control to be less effective during that time. It’s also possible for hormonal birth control to make ella less effective. Plan B doesn’t have this interaction.

Certain enzymes (proteins) in the body break down and remove Plan B and ella after you take it. Other medications can affect those enzymes. If you take them along with Plan B or ella, they can make these emergency contraception pills less effective.

The following medications can make Plan B and ella less effective:

  • Barbiturates, such as phenobarbital

  • Carbamazepine (Tegretol)

  • Oxcarbazepine (Trileptal)

  • Phenytoin (Dilantin, Phenytek)

  • St. John’s wort — an OTC herbal product

  • Topiramate (Topamax)

  • Some HIV medications, such as efavirenz (Sustiva)

This isn’t a complete list of medications that interact with Plan B or ella. Always check with your healthcare provider or pharmacist for interactions before taking emergency contraceptives. 

How to save on Plan B and ella

Plan B and ella are available as brand-name medications. But you can also find Plan B as a lower-cost generic. GoodRx can help you navigate ways to save on your medication.

  • Save with GoodRx. GoodRx can help you save over 69% off the average retail price of the generic version of Plan B. Generic Plan B at certain pharmacies is as low as $12.27 with a free GoodRx discount. Ella's price at certain pharmacies is as low as $43.42 with a free GoodRx discount.

There are some extra ways you can save on Plan B:

  • Save with a coupon from the manufacturer. If you're purchasing brand-name Plan B without a prescription, the manufacturer has a $10 coupon available to download and print from your computer. Just present it at the register during your purchase.

  • Save with a rebate. If you've already purchased brand-name Plan B without a prescription, you can still save money. By submitting a copy of your sales receipt to the manufacturer's website, you can receive a rebate in the mail.

Can you take Plan B and ella together for emergency contraception?

No, you shouldn’t combine Plan B and ella. This can actually make them less effective. Plan B is a type of hormonal contraception. As discussed earlier, ella interacts with hormonal contraceptives.

The bottom line

Ella (ulipristal) and Plan B (levonorgestrel) are safe and effective options to help prevent pregnancy after unprotected sex. Plan B is available over the counter and has generic versions. Ella is a better option if it’s been 3 to 5 days since you had unprotected sex. But you’ll need a prescription to purchase it. If you aren't sure which option is better for you, discuss ella and Plan B with your healthcare provider or pharmacist.

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Why trust our experts?

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP
Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP, has over a decade of experience as a pharmacist, professor, and researcher. She was a full-time clinical professor in the pharmacy practice department at D’Youville School of Pharmacy before subsequently joining the faculty of the pharmacy practice department at the University at Buffalo School of Pharmacy and Pharmaceutical Sciences.
Christina Aungst, PharmD
Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.
Stacia Woodcock, PharmD
Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

References

A-S Medication Solutions. (2023). Ella- ulipristal acetate tablet [package insert].

Chao, Y. S., et al. (2018). Ulipristal versus levonorgestrel for emergency contraception: A review of comparative clinical effectiveness and guidelines. Canadian Agency for Drugs and Technologies in Health.

View All References (6)

Novel Laboratories, Inc. (2013). Levonorgestrel tablet [package insert]. DailyMed.

Office on Women’s Health. (2023). Emergency contraception.

Planned Parenthood. (n.d.). What’s the Plan B morning-after pill?

Planned Parenthood. (n.d.). Which kind of emergency contraception should I use?

The American College of Obstetricians and Gynecologists. (2015). Emergency contraception.

World Health Organization. (n.d.). Emergency contraception.

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

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