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Emergency Contraception

What is Emergency Contraception?

Emergency Contraception (EC) is a "back up" birth control method used to prevent pregnancy after unprotected sex, or when a contraceptive measure fails.  It is most effective if taken as soon as possible after unprotected sex.

There are several options for EC:  

1) Copper containing IUD

2) Ilipristal acetate (UPA, Ella)

3) Levonorgestrel (Plan B One Step)

All options are available at Washington University in St. Louis. We encourage you to book an appointment on line with any of our providers to discuss which option is right for you.  Next day appointments open up every evening in primary care. You can also walk in to speak with our triage nurse.  

The IUD is the most effective method in preventing pregnancy when inserted within 5 days of unprotected sex. It then gives you ongoing contraception for 12 years.   An appointment can usually be made within this time frame after speaking with a provider here at SHS. 

Ella is an anti-progestin pill.  It is the most effective emergency contraceptive pill. It is effective up to 5 days after unprotected sex and is available by prescription.

Plan B One-Step is an over the counter pill that contains concentrated doses of progestin, a hormone found in daily birth control pills.  It is effective up to 3 days after unprotected sex. 

The data is suggestive – but not definitive – that weight (greater than 165 lbs.) may affect the efficacy of the medicine​ in Plan B One-Step.

EC should only be used in emergency situations, including after unprotected sex, contraceptive failure, slippage, or breakage, a missed contraceptive shot, pill, patch, etc., or unwanted sex/sexual assault.

Emergency contraception may be used as many times as needed, but it should not substitute for regular contraception because it is not as effective as other forms of contraception.

EC does not protect against sexually transmitted infections (STIs) including HIV.  If you are concerned that you may have contracted an STI, you can schedule an appointment or visit SHS in person.

The “morning after” pill

EC is often referred to as the morning-after pill because it can be taken “the morning after” unprotected sex to help prevent pregnancy. EC is not an abortion pill. Mifepristone, formerly known as RU-486 and also called "the abortion pill," is a drug that induces abortion when administered in early pregnancy. This is totally different from any emergency contraceptive. EC cannot end a pregnancy that has already started.

How EC works

The IUD prevents pregnancy by affecting sperm viability and function.  It may also affect the egg and the lining of the uterus.  Ella and Plan B act by delaying or inhibiting ovulation.

EC is safe. EC is FDA-approved and has been used by millions of women around the world safely and effectively. Some women report minor side effects such as nausea, vomiting, cramping, fatigue, headache, dizziness, breast tenderness, and/or menstrual changes.

How can I get EC?

We encourage you to book an appointment on line​ with any of our providers to discuss which option is right for you.  Next day appointments open up every evening in primary care. You can also walk in to speak with our triage nurse who can help you. ​Plan B One-Step is available directly from our pharmacy during business hours or any pharmacy when SHS is closed.

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More EC information

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