Disclosure: This article may contain affiliate links. If you click a link and make a purchase, we may receive a commission at no additional cost to you. All opinions remain our own.
Emergency Contraception: Your Options and Timing at a Glance
If you’ve had unprotected sex, a condom failed, or you missed doses of your regular birth control, emergency contraception can help reduce the chance of pregnancy. According to the CDC, four emergency contraception options are available in the United States: the copper intrauterine device (Cu-IUD) and three types of emergency contraceptive pills (ECPs). All four can be used within 5 days of unprotected sex, but effectiveness generally declines the longer you wait, so acting quickly matters.
This guide explains what each option is, how timing and access differ, and what to do afterward. It is general education, not a recommendation for your specific situation — a clinician or pharmacist can help you decide which option fits your circumstances.
Act-Now Checklist
- Note the time. Write down roughly when the unprotected sex happened — timing determines which options are still on the table.
- Check pill access first if pills are your choice. One type of levonorgestrel emergency contraceptive pill is available over the counter in pharmacies and stores; ulipristal acetate requires a prescription in the United States.
- Ask about the copper IUD if you’re within 5 days. It requires an appointment with a clinician for placement, so call a clinic or pharmacy as soon as possible to check same-day or next-day availability.
- Take pills as soon as possible. The CDC notes that emergency contraceptive pills should be taken as soon as possible within 5 days of unprotected sex.
- If you vomit within 3 hours of taking a pill, contact a pharmacist or provider — another dose may be recommended.
- Plan your next pregnancy test. If you don’t have a withdrawal bleed (period-like bleeding) within 3 weeks, take a pregnancy test.
- Think about ongoing contraception before you need emergency contraception again — see the follow-up section below.
The Two Categories: Copper IUD vs. Emergency Contraceptive Pills
Emergency contraception falls into two broad categories, each with different timing windows, access requirements, and follow-up needs.
Copper IUD (Cu-IUD)
- Timing: Can be placed within 5 days of unprotected sex. In some cases, when the day of ovulation can be estimated, a clinician may place it more than 5 days after intercourse, as long as it isn’t more than 5 days after ovulation.
- Access: Requires an in-person visit with a clinician for insertion — it cannot be self-administered.
- Effectiveness: The CDC describes the copper IUD as highly effective as emergency contraception.
- Ongoing contraception: Unlike the pill options, the copper IUD can be left in place and continued as an ongoing, long-term method of birth control (it can stay in place for years), so one visit can cover both emergency and future contraception.
Emergency Contraceptive Pills (ECPs)
Three pill formulations are used for emergency contraception in the U.S.:
- Ulipristal acetate (UPA): A single 30 mg dose, available by prescription.
- Levonorgestrel (LNG): A single 1.5 mg dose, or a split dose (0.75 mg followed by another 0.75 mg 12 hours later). Some LNG products are available over the counter without a prescription.
- Combined estrogen and progestin (Yuzpe regimen): Two doses taken 12 hours apart. The CDC notes this regimen is less effective than UPA or LNG and is linked to more nausea and vomiting.
- Timing: Should be taken as soon as possible, within 5 days of unprotected sex. The CDC’s evidence summary notes that UPA and LNG have similar effectiveness within 3 days, but UPA has been observed to work better than LNG between 3–5 days after unprotected sex. Pregnancy rates were generally slightly higher across formulations when pills were taken later in the 5-day window.
- Access: Varies by product — some ECPs are available over the counter, while others require a prescription in the United States.
- A note on body weight: The CDC notes that the LNG pill might be less effective for people with obesity compared with UPA — a detail worth discussing with a pharmacist or clinician when choosing between pill types.
Timing Window at a Glance
Every emergency contraception option in the U.S. works within roughly the same outer window — up to 5 days after unprotected sex — but “sooner is better” applies across the board:
- Copper IUD: Up to 5 days after unprotected sex (occasionally longer if ovulation timing is known).
- Ulipristal acetate (UPA) pill: Up to 5 days; consistent effectiveness has been observed within this window.
- Levonorgestrel (LNG) pill: Up to 5 days, though effectiveness may decrease more after day 3 compared with UPA.
- Combined estrogen-progestin pill: Up to 5 days; generally the least effective of the pill options and more likely to cause nausea.
What Happens After: Follow-Up and Ongoing Contraception
What comes next depends on which option you used:
After ulipristal acetate (UPA)
- Wait at least 5 days before starting or resuming hormonal birth control (the pill, patch, ring, or hormonal methods started by a clinician), since starting hormonal contraception too soon may reduce UPA’s effectiveness.
- Use condoms or abstain from sex for 7 days after starting or resuming regular contraception, or until your next period — whichever comes first.
- A non-hormonal method (such as condoms) can be started immediately.
- Take a pregnancy test if you don’t have a withdrawal bleed within 3 weeks.
After levonorgestrel (LNG) or the combined regimen
- Regular contraception can be started or resumed right away — no waiting period is needed.
- Use condoms or abstain from sex for 7 days after starting or resuming your regular method.
- Take a pregnancy test if you don’t have a withdrawal bleed within 3 weeks.
If you’re thinking about a longer-term contraception plan going forward, our birth control and contraception guide walks through the range of ongoing methods available.
Managing Nausea
Nausea and vomiting are possible with any ECP, but the CDC notes that LNG and UPA cause less nausea than the combined estrogen-progestin regimen. Routine use of anti-nausea medication before taking ECPs isn’t generally recommended, but a pharmacist or clinician may consider it depending on your situation. If you vomit within 3 hours of taking a dose, another dose is generally recommended — check with a pharmacist or provider promptly.
What Emergency Contraception Does Not Do
- It does not protect against sexually transmitted infections (STIs), including HIV. The CDC notes that consistent, correct use of external (male) condoms reduces STI risk, and that internal (female) condoms may offer some protection, though data are more limited. If STI exposure is also a concern, our STI and sexual health resource covers testing and prevention options.
- It is not a routine or ongoing method of birth control. Emergency contraception is intended for occasional, after-the-fact use — not as a substitute for a regular contraceptive method.
- It is intended to prevent pregnancy before it is established — it is not the same as medication used to end an existing, confirmed pregnancy, and it will not work if a pregnancy has already been confirmed.
Limitations and Who Should Be Cautious
- Effectiveness is not guaranteed for any method, and it generally decreases the longer you wait after unprotected sex.
- The CDC notes that advance provision of ECPs (getting a supply ahead of time so it’s on hand when needed) has been shown to increase use when it’s needed, but has not been shown to reduce pregnancy rates at a population level — advance access is about convenience and speed of use, not a guarantee of lower pregnancy risk.
- Choosing between options can depend on factors like how many days have passed, body weight, whether you want ongoing contraception at the same visit, and access to a clinician — a healthcare provider or pharmacist is best positioned to help weigh these for your situation.
- If you don’t have a withdrawal bleed within 3 weeks of taking ECPs, or if you have symptoms of pregnancy, take a pregnancy test and follow up with a clinician.
Frequently Asked Questions
How long after unprotected sex can I still use emergency contraception?
All current options in the U.S. — the copper IUD and the three types of emergency contraceptive pills — can be used within 5 days of unprotected sex, per CDC guidance. That said, taking pills as soon as possible improves the chance they’ll work, and the copper IUD is generally the most effective option across the full window.
Can I get emergency contraception without a prescription?
It depends on the product. Some levonorgestrel emergency contraceptive pills are available over the counter in the United States, while ulipristal acetate requires a prescription. The copper IUD requires an appointment with a clinician for placement. A pharmacist can tell you what’s available without a prescription where you are.
Does emergency contraception protect against STIs?
No. The CDC is clear that emergency contraception does not protect against sexually transmitted infections, including HIV. Condoms, used consistently and correctly, reduce STI risk, and pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention when taken as prescribed.
What if I’m not sure which option is right for me?
That’s a good question for a pharmacist or clinician rather than something to decide alone from general information. They can factor in how much time has passed, your health history, and whether you’d also like to start an ongoing method of birth control at the same time. Our reproductive health and preventive care page can help you find that kind of visit.
Educational Disclaimer
This article is for general educational purposes only and does not constitute medical advice, diagnosis, or treatment. It is not a substitute for an individualized assessment or recommendation from a licensed healthcare provider. Emergency contraception options, timing windows, and access rules can vary and may be updated as guidance changes; always confirm current details with a pharmacist, clinic, or your healthcare provider. If you have questions about your specific situation, please consult a qualified healthcare professional.