Can You Rely on Emergency Contraceptives Within 7 Days?

Emergency contraceptive pill

Can birth control pills be taken on the 7th day and still be effective for same-day intercourse? Is it necessary to wait until the 8th day for them to be effective in preventing pregnancy?

SHI, 10~19 year old female. Ask Date: 2015/12/13

Dr. Zhang Kunmin reply Obstetrics and Gynecology

Hello, the correct way to take oral contraceptive pills (OCPs) for preemptive contraception is to start taking them on the first day of your menstrual period (at the latest, you should start within seven days of the onset of menstruation; the later you start, the less effective they will be).
The usage cycle is 21 days, followed by a 7-day break.
The mechanism of action of OCPs is to suppress ovulation, and it is crucial to take them consistently every day without missing any doses or interruptions; their contraceptive effectiveness is 99%.
OCPs will reach their peak concentration in the bloodstream after seven days of consistent use, at which point their contraceptive effect will be optimal.
If you have not completed seven days of use, it is advisable to use additional protection, such as condoms.
For the second pack, you should start taking the pills on the eighth day after the break (regardless of whether your period has ended).
If you take them regularly without missing any doses, they will provide contraceptive protection for 28 days.
The best method of contraception is dual protection, which means that the male partner uses condoms while the female partner takes oral contraceptive pills, enhancing contraceptive safety.
Thank you! Wishing you peace and health, Dr.
Zhang.

Reply Date: 2015/12/13

More Info

Emergency contraceptives (EC), commonly referred to as the "morning-after pill," are designed to prevent pregnancy after unprotected intercourse or contraceptive failure. The effectiveness of these pills can vary depending on the type of emergency contraceptive used and the timing of administration relative to the unprotected intercourse.

There are two primary types of emergency contraceptive pills:
1. Levonorgestrel (Plan B One-Step and generics): This type of EC is most effective when taken within 72 hours (3 days) after unprotected sex. However, it can be taken up to 5 days after intercourse, but its effectiveness diminishes significantly with each passing day. It is important to note that if you take it on the 7th day after unprotected intercourse, it is unlikely to be effective.

2. Ulipristal Acetate (Ella): This is another form of emergency contraception that can be taken up to 120 hours (5 days) after unprotected sex. Unlike Levonorgestrel, Ulipristal maintains its effectiveness throughout the 5-day window, making it a better option for those who may not be able to take it immediately after intercourse.

To address your specific question: If you have unprotected intercourse and are considering taking emergency contraception, it is crucial to take it as soon as possible. If you wait until the 7th day after the event, the chances of preventing pregnancy are significantly reduced, especially if you are using Levonorgestrel.
Regarding your concern about whether you must wait until the 8th day to take the pill, the answer is no. You should take the emergency contraceptive as soon as possible after unprotected intercourse. Waiting until the 8th day would likely mean that the window for effective prevention has passed, particularly with Levonorgestrel.

In summary, if you have had unprotected intercourse, you should take emergency contraception as soon as possible. If you are within the 72-hour window, Levonorgestrel is a viable option, while Ulipristal can be taken up to 120 hours after intercourse. However, waiting until the 7th day or beyond is not advisable, as the effectiveness of these medications significantly decreases after the initial days following unprotected sex. If you have any further questions or concerns about your contraceptive options or sexual health, it is always best to consult with a healthcare provider for personalized advice and guidance.

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