Effectiveness of Emergency Contraceptive Pills: Your Questions Answered

What is the effectiveness of emergency contraception?

I had unprotected intercourse with my boyfriend on the night of August 21 around 11 PM, and I took emergency contraception the morning of August 22.
However, my boyfriend did not use any protection on the 22nd and 23rd, and there was residual ejaculation inside.
Does the effectiveness of the emergency contraception last until the 23rd? Should I take it again? Thank you, doctor.

Miss Tong, 20~29 year old female. Ask Date: 2015/08/23

Dr. Cao Guotao reply Obstetrics and Gynecology

Hello, the effectiveness of emergency contraceptive pills is to take them within 48 hours after sexual intercourse, with an efficacy of 80%.
Therefore, it is recommended to use contraception beforehand.
Wishing you good health.

Reply Date: 2015/08/23

More Info

Emergency contraceptive pills (ECPs) are designed to prevent pregnancy after unprotected intercourse or contraceptive failure. The effectiveness of these pills can vary based on several factors, including the timing of ingestion relative to the unprotected intercourse, the type of emergency contraceptive used, and individual physiological factors.

In your case, you had unprotected intercourse on the night of August 21 and took an emergency contraceptive pill the following morning on August 22. The primary types of emergency contraceptive pills available include levonorgestrel (Plan B One-Step) and ulipristal acetate (Ella). Levonorgestrel is most effective when taken within 72 hours (3 days) after unprotected intercourse, while ulipristal acetate can be effective up to 120 hours (5 days) after intercourse.

Since you took the emergency contraceptive pill on August 22, it would still be effective for the unprotected intercourse that occurred on the night of August 21. However, if you had additional unprotected intercourse on August 22 and 23, the effectiveness of the pill you took may not cover these subsequent events, especially if the pill was not taken immediately after those encounters.

If you are concerned about the possibility of pregnancy due to the unprotected intercourse on August 22 and 23, it is advisable to take another dose of emergency contraception as soon as possible. If you are using levonorgestrel, it is recommended to take it within 72 hours of the unprotected intercourse. If you are using ulipristal acetate, it can be taken within 120 hours.
It is also important to note that ECPs are not intended to be used as a regular form of contraception and are less effective than regular contraceptive methods. If you find yourself needing emergency contraception frequently, it may be beneficial to discuss long-term contraceptive options with your healthcare provider.

In addition, after taking emergency contraception, you may experience some side effects such as nausea, fatigue, headache, or changes in your menstrual cycle. If your period is delayed by more than a week after the expected date, it is advisable to take a pregnancy test to confirm whether or not you are pregnant.

In summary, since you had unprotected intercourse on August 22 and 23 after taking the emergency contraceptive pill, it is recommended to take another dose of emergency contraception as soon as possible to maximize your chances of preventing pregnancy. Always consult with a healthcare provider for personalized advice and to discuss the most effective contraceptive methods for your situation.

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