the Effectiveness Duration of Emergency Contraceptive Pills

The effectiveness duration of the emergency contraceptive pill Ella?

Hello, doctor.
I had unprotected intercourse with my girlfriend (not during her fertile period) on the early morning of November 26, and there was some fluid involved.
To be safe, I took the emergency contraceptive pill Ella (ulipristal acetate) at around 11 PM that same day.
We had intercourse again on the evening of November 30.
Does the instruction stating that the medication should be taken within 120 hours after intercourse mean that its effectiveness lasts for 120 hours? Since there was an interval of about four days, do I need to take the medication again? Thank you for your response.

Lao Die, 40~49 year old female. Ask Date: 2023/12/01

Dr. Cao Guotao reply Obstetrics and Gynecology

Hello, if it is during the dangerous period, it is recommended to take emergency contraception just in case.
Wishing you good health.

Reply Date: 2023/12/01

More Info

Emergency contraceptive pills (ECPs), such as Ella (ulipristal acetate), are designed to prevent pregnancy after unprotected intercourse or contraceptive failure. Understanding their effectiveness duration is crucial for proper usage.

Ella is effective for up to 120 hours (5 days) after unprotected intercourse. This means that if you have unprotected sex, you can take Ella anytime within that 120-hour window to reduce the risk of pregnancy. However, the effectiveness of the pill does not extend beyond this period. Therefore, if you had unprotected sex again on November 30, which is four days after taking Ella, you would need to take another dose of the emergency contraceptive pill, as the first dose would not provide protection for this second instance of unprotected intercourse.

It’s important to note that while Ella can be taken at any time within the 120-hour window, its effectiveness may decrease the longer you wait to take it after unprotected sex. Studies have shown that Ella is most effective when taken as soon as possible after unprotected intercourse. The sooner you take it, the better the chances of preventing pregnancy.

In your case, since you had unprotected sex on November 26 and took Ella that same day, you were within the effective time frame. However, since you had another instance of unprotected sex on November 30, you should take another dose of Ella to ensure you are protected against pregnancy from that encounter.

Additionally, it’s worth mentioning that ECPs like Ella do not terminate an existing pregnancy; they work primarily by delaying ovulation. If ovulation has already occurred, the pill may not be effective. Therefore, if you are concerned about the possibility of being pregnant after taking Ella, it is advisable to take a pregnancy test if your next period is delayed by more than a week.

In terms of side effects, some women may experience nausea, fatigue, headache, or changes in their menstrual cycle after taking emergency contraceptive pills. These side effects are generally mild and temporary. If you experience severe side effects or have concerns about your health, it’s important to consult a healthcare professional.

In summary, since you had unprotected sex again on November 30, you should take another dose of Ella as soon as possible to ensure you are protected against pregnancy. Always consult with a healthcare provider for personalized advice and to discuss any concerns regarding emergency contraception and its use.

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