Emergency Contraception: Effectiveness and What to Expect After Use

Emergency contraceptive pill

My period started on November 1 and ended completely on November 12.
On the night of the 12th, I had sexual intercourse and accidentally ejaculated inside.
I went to the pharmacy that night and bought Plan B, which contains one tablet of 1.5 mg.
Is it effective? Do I need to buy a second dose? Also, during this period, will I definitely experience bleeding? Does everyone experience this?

Xiao Zi Xiao Jie, 20~29 year old female. Ask Date: 2015/11/14

Dr. Zhang Kunmin reply Obstetrics and Gynecology

Hello,
There are mainly two types of emergency contraceptive pills.
The first category includes medications such as Postinor, Postinor-2, and Postinor-3, each containing two tablets of 0.75 mg of levonorgestrel.
The recommended usage is to take one tablet within 72 hours after unprotected intercourse, followed by a second tablet 12 hours later.
Recent studies have shown that a single dose of 1.5 mg of levonorgestrel is also effective.
Therefore, the second category of medications, such as EllaOne, contains only one tablet of 1.5 mg of levonorgestrel, which should be taken within 72 hours after intercourse.
The effectiveness of emergency contraception is approximately 95% if taken within 24 hours, but it decreases significantly after that, dropping to 58% by the third day.
If your period is delayed by a week, it is recommended to take a urine pregnancy test to confirm whether you are pregnant or to consult a gynecologist.
Emergency contraceptive pills contain high doses of levonorgestrel, primarily functioning to inhibit or delay ovulation.
The dosage of one pill is equivalent to taking eight regular oral contraceptive pills, making it a high-dose medication.
Frequent and long-term use may increase the risk of infertility, so it is not recommended as a regular contraceptive method.
Additionally, using emergency contraceptive pills more than once a month can lead to menstrual irregularities.
For those who are sexually active, the best contraceptive method is dual contraception, which involves the male partner using condoms while the female partner takes oral contraceptives to enhance contraceptive safety.
The impact of emergency contraceptive pills on menstruation can vary; it may not necessarily cause periods to come earlier or later.
If you experience prolonged bleeding or if your period is more than a week late, it is advisable to check for pregnancy.
Thank you! Wishing you peace and health.

Dr.
Zhang

Reply Date: 2015/11/14

More Info

Emergency contraception (EC) is a crucial option for individuals who have had unprotected intercourse and wish to prevent an unintended pregnancy. The effectiveness of emergency contraception, such as Plan B (levonorgestrel) or Ella (ulipristal acetate), depends on several factors, including the timing of administration relative to ovulation and the individual's menstrual cycle.

In your case, you mentioned that your last menstrual period started on November 1 and ended on November 12. If you had unprotected intercourse on December 12 and took a single dose of emergency contraception (1.5 mg of levonorgestrel), it is important to understand how this medication works. Levonorgestrel is most effective when taken within 72 hours (3 days) after unprotected intercourse, but it can still reduce the risk of pregnancy if taken within 120 hours (5 days). Since you took it on the same day as the intercourse, you are within the optimal time frame for effectiveness.

Regarding your question about whether you need to buy a second dose, typically, one dose of levonorgestrel is sufficient for emergency contraception. There is no need to take a second dose unless you vomit within two hours of taking the first dose, in which case you should consult a healthcare provider for further guidance.

After taking emergency contraception, it is common for individuals to experience some changes in their menstrual cycle. Some may experience spotting or bleeding within a few days of taking the medication, while others may have their next period arrive earlier or later than expected. It is important to note that not everyone will experience bleeding after taking emergency contraception, and the absence of bleeding does not necessarily indicate pregnancy.
If your next period is delayed by more than a week from when you expect it, it is advisable to take a pregnancy test to confirm whether or not you are pregnant. This is a standard recommendation following the use of emergency contraception, as it helps to ensure that you have not become pregnant despite taking the medication.

In summary, taking a single dose of 1.5 mg of levonorgestrel after unprotected intercourse is effective, and you do not need to take a second dose unless advised by a healthcare professional. Expect some changes in your menstrual cycle, but not everyone will experience bleeding after taking the medication. If your period is significantly delayed, consider taking a pregnancy test for peace of mind. Always consult with a healthcare provider for personalized advice and to discuss any concerns you may have regarding emergency contraception or your reproductive health.

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