What’s the best emergency contraception option for me?

Key takeaways:

• Timing, your health, and your long-term plans are all important factors in choosing the right emergency contraception for you. 
• The best option can change, so it’s smart to consider all these factors any time you need emergency contraception (though important to remember, it is not a replacement for regular birth control).
• Over-the-counter and prescription emergency contraception are available online through Nurx.

Accidents happen—and when they do, having access to emergency contraception can make a big difference. Whether a condom broke, you missed a pill, or you weren’t using birth control at all, there are safe, effective options available to help prevent pregnancy after unprotected sex.

Emergency contraception is a backup—not a replacement for regular birth control—but it’s a powerful tool to have in your toolkit. The most important thing to know? Timing matters. The sooner you take it, the more effective it is.

There are a few different types of emergency contraception, and each works a little differently. Some are available over the counter, while others require a prescription. We’ll walk you through the options, explain how they work, and help you understand what might be best for your body and your situation.

What is emergency contraception, and how does it work?

Emergency contraception is a backup method of birth control that helps prevent pregnancy after unprotected sex or when your regular method didn’t work as expected. Whether a condom broke, you missed a pill, or didn’t use birth control at all, emergency contraception can help prevent a pregnancy.

Most emergency contraceptives work by delaying ovulation—that’s when your ovary releases an egg. If no egg is released, there’s nothing for sperm to fertilize, which means pregnancy can’t happen. It’s important to know that emergency contraception won’t harm an existing pregnancy and isn’t the same as an abortion—it simply prevents pregnancy from starting.

Your body’s hormones are carefully timed to release an egg each cycle. Emergency contraception steps in to temporarily shift that timing. There are a couple of different types: some contain a higher dose of the same hormone found in many birth control pills (levonorgestrel), while others (like Ella®) use a different medication that’s especially good at delaying ovulation.

Delaying ovulation to prevent pregnancy

Sperm can live in the body for up to five days, so even if ovulation is still a few days away, there’s a chance for fertilization if an egg is released. Emergency contraception works by pressing pause on ovulation long enough for the sperm to die off naturally.

The key is timing—taking emergency contraception as soon as possible gives it the best chance to work. It’s like asking your body to wait a little before ovulating, so there’s no egg available for fertilization.

Types of emergency contraceptives

When you need emergency contraception, having clear, supportive guidance can make all the difference. The right option for you depends on timing, access, and your personal health history. Some methods are more effective than others, and a few can even double as long-term birth control.

Understanding your choices helps you act with confidence when the unexpected happens. Here’s a breakdown of the most common types—and how to choose what’s best for your body and your life.

Morning-after pills

The morning-after pill is a widely used form of emergency contraception. These pills work by delivering a dose of hormones that delay ovulation—giving your body time to prevent pregnancy before it can begin.

At Nurx, you can access:

• Levonorgestrel 1.5mg pills (generic Plan B): Available over-the-counter and most effective when taken within 72 hours after unprotected sex.
• Ella® (ulipristal acetate): Prescription-only, but more effective later in the 5-day window and for people with higher body weight.

Both options come as a single pill and are easy to use, even in stressful situations.

Levonorgestrel emergency contraception pills

Levonorgestrel-based pills, like Plan B One-Step® and generics, contain a hormone that’s been safely used in birth control for decades. They’re most effective when taken within 24 hours of unprotected sex—about 95% effective—but the sooner, the better.

Keep in mind:

• Effectiveness decreases each day, dropping to around 61% by day three
• They work best for those under 165 pounds
• Side effects may include nausea, fatigue, headache, or temporary changes to your period

These pills are widely available and often the quickest option.

Ulipristal acetate (Ella®)

Ella® is an emergency contraception pill that remains consistently effective for up to five days after unprotected sex. It works by blocking progesterone receptors to more reliably delay ovulation, even if you’re already close to ovulating.

Why people choose Ella®:

• It’s about 85% effective across the entire 5-day window
• It may be a better option if you weigh more than 165 pounds
• Side effects are similar to levonorgestrel

You’ll need a prescription, but it’s easy to get online through Nurx, with fast, discreet delivery.

Copper IUD (Paragard®)

If you’re looking for the most effective emergency contraception available, the copper IUD is it. When inserted by a healthcare provider within five days of unprotected sex, it’s over 99% effective—and it keeps working as birth control for up to 10 years.

Why it’s a great choice:

• No hormones, so it’s suitable for those who can’t or prefer not to use hormonal methods
• Offers long-term protection with one-time insertion

It may cause cramping during insertion and heavier periods for some. It does require an in-person appointment, but for many, the long-term peace of mind is worth it.

Using regular birth control pills as emergency contraception

If you can’t access dedicated emergency contraception, certain combined birth control pills (those containing both estrogen and progestin) can be used in higher doses using the Yuzpe method.

This method involves taking:

• A specific number of pills in two doses, 12 hours apart
• Only works with certain formulations (check with a provider)
• May cause stronger side effects like nausea or vomiting, similar to Ella®

While not the first choice, it’s a useful option in a pinch—especially if you already have the right pills on hand. You should always see a provider for guidance before using regular birth control pills as emergency contraception. 

Factors that will affect your choice

There’s no single “right” emergency contraception for everyone—and that’s okay. Your body, your timing, and your health all play a role in determining which option will work best for you. Taking a moment to understand those factors can help you choose a method that’s not only effective but also safe and supportive of your needs right now.

Where you are in your menstrual cycle

Where you are in your menstrual cycle matters, especially if you’re close to ovulation. That’s typically around the middle of your cycle, when your chances of getting pregnant are highest. In this fertile window, certain methods like the copper IUD offer the most reliable protection since they work in multiple ways beyond just delaying ovulation.

If you’re earlier or later in your cycle, your risk of pregnancy may be lower, but emergency contraception is still recommended after unprotected sex. 

Tools like period-tracking apps or calendars can help you get a general sense of your cycle, but keep in mind that things like stress, travel, and illness can shift ovulation, which makes emergency contraception an important safety net no matter what.

Your body weight

Weight can affect how well some emergency contraceptive pills work. Research shows that levonorgestrel-based pills (like Plan B® and its generics) may be less effective for people who weigh over 165 pounds—and especially for those over 195 pounds.

That doesn’t mean they’re completely ineffective, but it does mean the risk of pregnancy may be higher. If you fall into that range, you might want to consider Ella® or a copper IUD instead:

• Ella® tends to hold its effectiveness better across different body weights, though some decrease is still possible at higher weights.
• The copper IUD isn’t affected by weight at all, making it the most consistent option no matter your size.

If you’re unsure, a provider can help you decide which method gives you the best protection based on your unique body and health.

Existing pregnancy

Emergency contraception works by preventing pregnancy—it won’t end a pregnancy that’s already begun. If it’s been more than a few days since unprotected sex, or if you’re concerned about a possible earlier pregnancy, it’s a good idea to take a pregnancy test first.

How to use emergency contraception safely

Emergency contraception is most effective when you understand how—and when—to use it. Whether it’s a backup for a birth control slip or a just-in-case plan, knowing the right steps can help you protect your reproductive health with confidence.

Having a plan in place before you need it can reduce stress when time matters. Many people choose to keep emergency contraception on hand, just in case. When you know how to use it correctly, you can act quickly and avoid second-guessing in an already vulnerable moment.

What to do after unprotected sex

If you’ve had sex without birth control—or if something didn’t go as planned, like a missed pill or broken condom—take a breath. You have options, and there’s still time to act.

• Check the clock: Emergency contraception works best when taken as soon as possible.
• Under 72 hours? A levonorgestrel pill (like Nurx Emergency Contraceptive) is widely available and easy to take.
• Up to 5 days? A prescription option like Ella®, or a copper IUD, may be more effective, especially if you’re closer to ovulation.

Follow the instructions on the package exactly—most emergency contraceptive pills are taken as a single dose. Don’t double up or combine methods unless directed by a healthcare provider; doing so won’t make them more effective and could increase side effects.

Until your next period arrives (and confirms that the method worked), it’s safest to use barrier protection like condoms if you have sex again.

What about your regular birth control?

If you’re already using hormonal contraception, you might be wondering how emergency contraception fits in.

• Taking Plan B® (or another levonorgestrel option)? You can start or continue your regular birth control right away.
• Taking Ella® (ulipristal acetate)? It works a little differently. You’ll need to wait five full days before starting or resuming any hormonal birth control (pill, patch, ring, etc.). Starting too soon could interfere with how well Ella® works.

During that five-day window, use condoms for any sex—and keep using them for seven days after restarting your regular method (or until your next period, if you’re using progestin-only pills).

Using long-acting methods like the shot or implant? Your provider can guide you through the timing based on your specific method and needs.

When to reach out to a health care provider

While emergency contraception is safe and effective for most people, having the support of a healthcare provider can make a big difference—especially if you’re unsure which method is right for you.

A provider can:

• Help you choose between pill options or a copper IUD
• Prescribe Ella®, if clinically appropriate
• Talk you through side effects and what to expect
• Discuss ongoing birth control options that match your lifestyle

You don’t have to wait for an in-person appointment. At Nurx, licensed providers are available online to answer questions and prescribe what you need—quickly, discreetly, and with your whole health in mind.

Your body, your backup plan

Emergency contraception is a safe, effective way to take control when things don’t go according to plan. Whether it’s a missed pill, a broken condom, or unexpected sex without protection, having a backup option—like Plan B®, Ella®, or a copper IUD—can make a big difference in preventing pregnancy and easing your peace of mind.

Each method has its own strengths. Levonorgestrel pills are easy to access and work well when taken quickly. Ella® offers more reliable protection later in the window, and the copper IUD not only prevents pregnancy with over 99% effectiveness—it can also become your long-term birth control method.

Frequently Asked Questions (FAQ):

What is the most effective form of emergency contraceptive?

The copper IUD is the most effective option. When inserted by a provider within five days of unprotected sex, it’s over 99% effective at preventing pregnancy—and it offers long-term protection, too.

Which is the best emergency contraceptive pill?

Ella® (ulipristal acetate) is more effective than levonorgestrel-based pills, especially between days 3 and 5 after unprotected sex. It requires a prescription but offers a longer window of protection.

Which morning pill is the most effective?

Ella® stays effective for up to 5 days after unprotected sex, making it a great option if you’re later in the emergency window.

Which emergency contraception has the fewest side effects?

Levonorgestrel pills (like Plan B One-Step® or Nurx Emergency Contraceptive) are typically well-tolerated and may have similar side effects than Ella®. Most people experience only mild symptoms, like temporary nausea or changes in their period.

We’re here to help

Remember, choosing emergency contraception is a responsible and empowering choice. We’re here to make sure you get the care you need, without judgment. Through Nurx, you can access both over-the-counter emergency contraception and prescription-strength Ella®.

For longer-term protection, we can also help you find the right birth control method for you. We provide access to over 50 birth control options and expert guidance to ensure you find the perfect fit. Find the right birth control for you and get started today.

The information provided is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon this content for medical advice. If you have any questions or concerns, please talk to a medical professional.

Services not offered in every state. Medications prescribed only if clinically appropriate, based on completion of required consultation. Individual results may vary.

Ella® (Ulipristal Acetate tablet, 30mg), Rx only, is an emergency contraceptive used to prevent pregnancy up to five days (120 hours) after unprotected sex. Ella® may cause side effects, including headache, nausea, and stomach pain. If you would like to learn more about Ella®, please see the full prescription information here. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit MedWatch: https://www.fda.gov/Safety/MedWatch/default.htm or call 1-800-FDA-1088.

Levonorgestrel tablet 1.5 mg, intended to reduce the chance of pregnancy after unprotected sex, may cause side effects, including dizziness, abdominal pain, diarrhea, headache, fatigue, irregular menstruation, breast tenderness, nausea or spotting. If you would like to learn more about Levonorgestrel tablet 1.5 mg, please see product information here. Use as directed.

Paragard®, Rx only, is indicated for prevention of pregnancy. This drug may cause side effects, including anemia, pain during sex, backache, and vaginal discharge. If you would like to learn more, see full prescribing information, here [hyperlink the word “here” and insert proper daily med page for the drug or TM  page for compounds, as applicable]. You are encouraged to report negative side effects to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

Learn more about Paragard® at paragard.com. All product names, manufacturer or distributor names, logos, trademarks, and registered marks (Paragard®) are the property of their owners and are for identification purposes only. Product Marks do not imply any affiliation, endorsement, connection, or sponsorship by their owner(s) with Nurx.

Paragard® is not offered through Nurx. Learn more at paragard.com. All product names, manufacturer or distributor names, logos, trademarks, and registered marks (“Product Marks”) are the property of their owners and are for identification purposes only. Product Marks do not imply any affiliation, endorsement, connection, or sponsorship by their owner(s) with Nurx.

Don’t use Paragard® if you are or may be pregnant, have fibroids, a pelvic infection including pelvic inflammatory disease (PID), get infections easily, certain cancers, unexplained bleeding, Wilson’s disease, or a copper allergy. IUDs, including Paragard, have been associated with an increased risk of PID. Pregnancy with Paragard® is rare but can be life threatening and cause infertility or loss of pregnancy.Tell your HCP you have Paragard®before having an MRI or a medical procedure using heat therapy. At first, periods may become heavier and longer with spotting in between.

Additional common side effects include anemia, pain during sex, backache, and vaginal discharge.

Paragard® does not protect against HIV or STDs.