Emergency Contraception Options: Plan B, Ella, and the Copper IUD Compared

The condom broke, you missed a couple of pills, or things just happened, and now you're staring at the clock wondering what to do. Take a breath. You have more than one emergency contraception option, and you likely have more time than you think, but acting sooner makes every choice work better.

This guide walks through all four emergency contraception (EC) options available in the US, how each one works, how quickly you need to use it, and which is the most effective, so you can make a calm, informed decision.

What are my emergency contraception options?

There are four emergency contraception options available in the US: the copper IUD and three types of emergency contraceptive pills, ulipristal acetate, levonorgestrel, and combined oral contraceptives. In practice, most people choose between the two common pills (Plan B and ella) or an IUD placed by a clinician.

Here is the short version of what each one is:

• Levonorgestrel (Plan B and generics): a single pill, available over the counter without an age restriction.
• Ulipristal acetate (ella): a single pill that requires a prescription.
• Copper IUD: a small device placed in the uterus by a clinician; it can also stay in as ongoing birth control.
• Combined oral contraceptives: regular birth control pills taken in a specific EC dose, an older backup method used less often today.

How do emergency contraceptive pills work?

Emergency contraceptive pills work by preventing or delaying ovulation, the release of an egg. They do not induce an abortion and do not work if you are already pregnant. Because they rely on stopping ovulation, timing matters a great deal, the sooner you take them after unprotected sex, the better the odds.

This is also why EC is not the same as the abortion pill, a common point of confusion. EC simply reduces the chance that a pregnancy starts in the first place.

How long do I have to take emergency contraception?

You generally have a window of a few days, but the methods differ, and effectiveness drops the longer you wait. Here is the timing for each option:

• Levonorgestrel (Plan B): a single 1.5 mg dose, effective within 72 hours (3 days) of unprotected sex.
• Ulipristal acetate (ella): a single 30 mg dose, effective up to 120 hours (5 days).
• Copper IUD: most effective method, and can be placed within 5 days of unprotected intercourse.
• Levonorgestrel 52-mg IUD: in a multicenter trial, it was noninferior to the copper IUD when placed within 5 days, with less bleeding and discomfort.

Plan B vs. ella vs. the copper IUD: which is most effective?

The copper IUD is the most effective emergency contraception method, with a pregnancy rate of about 0.09% when inserted within 5 days, more than 99% effective. Among the pills, ulipristal acetate (ella) edges out levonorgestrel: pregnancy rates are roughly 1.4% for ulipristal versus about 2.2% for levonorgestrel, and ulipristal is more effective than levonorgestrel at all times up to 5 days and across all body weights.

Body weight is an important wrinkle. Levonorgestrel's effectiveness declines with higher body weight, with reduced efficacy reported around a BMI of 26 or higher (roughly 165 lb), while ulipristal acetate stays more effective across higher BMI ranges. If weight is a factor for you, ella or a copper IUD may be the better call. To put pill effectiveness in context, a single 1.5 mg dose of levonorgestrel taken within 72 hours has been shown to prevent over 84% of expected pregnancies, helpful, but clearly not as protective as an IUD.

How do I choose the right option for me?

The best choice depends on how much time has passed, your access, and whether you also want ongoing birth control. A few practical guideposts:

• Need something fast and over the counter, within 3 days: levonorgestrel (Plan B) is widely available without a prescription or age limit.
• It has been 3 to 5 days, or weight may reduce efficacy: ulipristal acetate (ella) maintains effectiveness up to 120 hours and across higher BMI, but needs a prescription.
• Want the most effective option and possibly long-term birth control: a copper or levonorgestrel IUD placed within 5 days.
• Note: do not combine ella with levonorgestrel or start certain hormonal birth control right after ella without clinician guidance, as they can interfere with each other.

When should I see a doctor?

Emergency contraception is safe for most people, but some situations call for a clinician. See a healthcare provider if you want an IUD placed (this always requires an appointment), if you need a prescription for ella, if your period is more than a week late after taking EC, or if you have severe lower-abdominal pain in the weeks afterward, which can rarely signal an ectopic pregnancy and is a medical emergency.

It is also worth talking with a clinician about a reliable ongoing birth control plan so you are not relying on EC repeatedly. If you would like personalized guidance, a licensed provider, including through a telehealth service like Nolla, can help you weigh your options and arrange a prescription or referral when appropriate.