Ella 101: How It Works, Usage Advice & More

    Ella is a common emergency contraceptive (also known as a morning-after pill) that, if used shortly after unprotected sex, can prevent you from becoming pregnant.

    If you’ve had unprotected sex and have concerns about becoming pregnant, using Ella within five days (120 hours) of the time you had sex can significantly reduce your pregnancy risk.

    Like all forms of contraception, Ella isn’t 100 percent effective. Below, we’ve explained how Ella works as a form of emergency contraception and how to use it. We’ve also listed some of the potential side effects you could experience after using Ella to prevent pregnancy.

    What is Ella?

    Ella is an emergency contraceptive pill, or “morning-after pill.” Unlike the regular pill, which you take daily in order to prevent yourself from becoming pregnant, Ella is designed for use after you have unprotected sex.

    Each Ella tablet contains a 30mg dose of ulipristal acetate, a selective progesterone receptor modulator that prevents pregnancy.

    Currently, Ella is the newest emergency contraceptive pill on the market. Ulipristal acetate, its active ingredient, was approved by the FDA in 2010. Plan B, an older type of morning-after pill that uses levonorgestrel, was approved in 1999 for over-the-counter use.

    Ella consists of one pill that contains a mild dose of ulipristal acetate. Unlike older morning-after pills, there is no need to take a second tablet for Ella to work effectively as a form of emergency contraception.

    How Does Ella Work?

    Ella works by preventing your ovaries from releasing an egg, a process that’s typically known as ovulation. By stopping the release of an egg, the active ingredient in Ella makes it less likely that you’ll become pregnant after having unprotected sex.

    The single dose of ulipristal acetate in Ella is strong enough to prevent you from ovulating for as long as five days after having sex.

    Sperm can typically survive in the vagina for up to five days. By preventing you from ovulating during this period, Ella reduces the risk of sperm coming into contact with an egg and causing you to become pregnant.

    Other morning-after pills, such as Plan B, also work by preventing your ovaries from releasing eggs. Unlike Plan B, Ella does not contain any hormones. Instead, it uses a drug known as a selective progesterone receptor modulator to control your body’s hormone levels.

    Is Ella Effective?

    Used properly, Ella is one of the most effective options available for preventing pregnancy after you have unprotected had sex.

    Unlike other morning-after pills, Ella is safe and effective as a form of contraception immediately after unprotected sex. This means that there’s no need to wait a day or longer before taking the medication.

    It also has a long effective period. Ella is designed for use within five days of having sex. This means that it’s effective for longer than options like Plan B, which is designed for use within three days after you have unprotected sex.

    If taken within five days of having unprotected sex, the general consensus according to organizations like Planned Parenthood is you’ll reduce your risk of becoming pregnant by approximately 85 percent. Studies confirm that people who took ulipristal acetate, the active ingredient in Ella, were 42 percent less likely to get pregnant than those who took levonorgestrel (Plan B Step-One) within the first 72 hours following unprotected sex, and a whopping 65 percent less likely within the first 24 hours after unprotected sex.

    Basically, the earlier you take Ella after sex, the more effective it will likely be at preventing pregnancy.

    How to Use Ella

    Ella is a prescription medication, meaning you’ll need to speak to a doctor before you can buy and use it to prevent pregnancy. 

    Because Ella is only effective for a five-day period after you have unprotected sex, it’s important to take it as soon as you become aware of your risk of becoming pregnant.

    Using Ella is simple. Unlike other morning-after pills, which often contain multiple pills that you need to take several hours apart, Ella only contains one pill.

    If you’ve had unprotected sex and have concerns about becoming pregnant, take Ella as soon after the sexual activity occurred as possible. You can use Ella up to five days (120 hours) after having unprotected sex.

    Although Ella is effective when taken within five days, it’s best to take it as early as you can after having sex. Using Ella after five days have passed since you had sex is not recommended, as it will not always be able to provide its full effects as a form of contraception.

    As a form of emergency contraception, Ella is ideal if:

    • You typically use a non-hormonal form of birth control but forgot to use it before or on the day you had unprotected sex.

    • Your partner wore a condom, but you’re worried that it might have broken or slipped off during sex.

    • You planned to use the pull out method, but your partner either didn’t pull out or pulled out too late.

    Although Ella isn’t the optimal form of emergency contraception for women who use hormonal birth control, you can also use it to stop pregnancy if you forgot to take your birth control pill on the day you had unprotected sex.

    If You Use Hormonal Birth Control (The Pill)

    If you use an oral contraceptive (the pill) for birth control, using Ella is not recommended for several reasons:

    • First, if you take your birth control pill as recommended, it should be more than 90 percent effective as a form of contraception. This mean that morning-after pills such as Ella aren’t usually necessary to prevent pregnancy.

    • Second, the active ingredient in Ella can affect your body’s hormone production. If you usually take the pill, its effects on your hormone levels can make Ella less effective as a form of emergency contraception.

      Likewise, the active ingredient in Ella can also make your birth control pills less effective for several days after use. If you usually take the pill but have missed a dose, alternative forms of emergency birth control, such as Plan B or the copper IUD, are better options.

    If you use the birth control pill and have recently taken Ella, stop using your birth control for six days after the unprotected sex occurred. When you start taking your birth control again, use a condom or abstain from sex for at least one week to ensure you’re protected from pregnancy.

    The above information applies to both the combined birth control pill (Yaz, Ortho Tri-Cyclen and Estrostep) and mini-pills that only use a progestin hormone.

    If You Use the Patch, Ring or Depo-Provera Injection

    Just like with the pill, if you use the patch, ring or injection for birth control, using Ella as a form of emergency contraception is not recommended.

    If you’ve recently had unprotected sex and forgot to use your patch or ring, Plan B or the copper IUD are the preferred options for preventing pregnancy. This is because the active ingredient in Ella can affect the effectiveness of the hormones used in the patch, ring and injection.

    Our guide to using the Ella morning-after pill goes into more detail about how to use Ella, as well as what to expect in the days and weeks after you take the medication.

    Side Effects of Ella

    Ella is an extremely safe medication. The vast majority of women who use it experience no side effects at all. Despite this, it’s possible to experience a range of minor side effects after you use Ella to prevent pregnancy. These include:

    • Headache. Headache is the most common side effect of Ella. Headaches from Ella are typically minor and become less intense as your body absorbs and processes the active ingredient in the medication. This side effect affects about 18 percent of women.

    • Nausea. It’s quite common to feel slightly nauseous after using Ella. According to study data, around 12 percent of women who use Ella experience some degree of nausea. In some cases, you might feel the need to vomit after taking the medication.

      If you vomit within three hours of taking Ella, the active ingredient in the medication may not be fully effective at preventing pregnancy. If this occurs, contact your doctor as soon as possible. Depending on your needs, they might prescribe a second dose of Ella.
    • Abdominal and upper abdominal pain. Nausea from Ella is often accompanied by a mild level of pain in the abdominals. A small percentage of women who take Ella also experience dysmenorrhea, or menstrual cramping.

    • Fatigue and dizziness. After taking Ella, you might feel slightly fatigued. Some women also feel mildly dizzy after using this medication. As with other side effects, these often fade away as your body absorbs and processes the medication.

    In addition to the side effects listed above, Ella can disrupt your period. You might get your next period earlier or later than normal. This is caused by the effects of ulipristal acetate, the active ingredient in Ella, on your body’s hormone production.

    You should get your next period within three weeks of the date you took the dose of Ella. If you don’t get your period within this time frame, consider taking a home pregnancy test.

    While these side effects can sound scary, it’s important to remember that most women who use Ella don’t experience them. Even the most common side effect — headaches — affects less than a quarter of women who use this medication.

    As for serious side effects, none have ever been reported from women who’ve used Ella as a form of emergency contraception. Simply put, Ella is a very safe medication.

    Our detailed guide to the side effects of the morning-after pill goes into more detail on what you can expect in the days and weeks after you take Ella, Plan B or other emergency contraception to prevent pregnancy.

    You can also learn more about the effects of morning-after pill on your period and reproductive health in our guide to the morning-after pill and your period.

    Ella and Body Mass Index (BMI)

    For most women, Ella is a highly effective way to reduce your risk of becoming pregnant after having unprotected sex.

    However, if you have a body mass index (BMI) of 30 or higher, Ella might not be fully effective as a form of emergency contraception. Other morning-after pills, such as Plan B, are also less effective for people with a BMI of 30 or higher.

    If this affects you, it’s best to use an alternative form of emergency contraception. The copper IUD, which is also highly effective at preventing pregnancy, does not become less effective in women with a BMI of 30 or higher, making it a good option if Ella isn’t suitable for you.

    Our complete guide to emergency contraception goes into more detail on the other ways you can prevent pregnancy after unprotected sex, including the copper IUD.

    Learn More About the Morning-After Pill

    Used properly, morning-after pills like Ella are highly effective at reducing your risk of becoming pregnant after unprotected sex.

    Our guide to how the morning-after pill works explains in more detail how medications like Ella prevent you from becoming pregnant. You can also learn more about Ella with our detailed FAQ page, which covers the most common questions about this medication.

    This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.