Effectiveness and Side Effects of Emergency Contraceptive Pills Explained

Taking emergency contraceptive pills?

Hello Doctor, I am the questioner of #146252.
Since my girlfriend is worried, I took her to buy the emergency contraceptive pill (Yuzpe regimen 1.5mg) today.
Our intimate activity occurred yesterday, May 18th, at 11 AM, and she took the medication today, May 19th, at around 5 PM.
Is this effective? A few hours after taking the pill, she experienced nausea and later developed abdominal pain.
Are these symptoms side effects of the medication?

Terry, 10~19 year old female. Ask Date: 2019/05/19

Dr. Huang Jianzhong reply Obstetrics and Gynecology

Due to my girlfriend's concerns, I took her to buy emergency contraceptive pills (Yuzpe regimen 1.5mg) to use after our intimate encounter that occurred yesterday, May 18, at 11 AM.
The medication was taken today, May 19, at around 5 PM.
Is this effective? Answer: Yes, it is effective.
After taking the medication, she experienced nausea and a desire to vomit 2-3 hours later, followed by abdominal pain.
Are these side effects of the medication? Answer: Yes, they are.

Reply Date: 2019/05/19

More Info

Emergency contraceptive pills (ECPs), such as the one your girlfriend took (Yuzpe regimen with 1.5 mg of levonorgestrel), are designed to prevent pregnancy after unprotected intercourse or contraceptive failure. The effectiveness of ECPs is highest when taken as soon as possible after the event, ideally within 72 hours, but they can be effective up to 120 hours (5 days) after unprotected sex, with decreasing efficacy over time. Since your girlfriend took the pill approximately 30 hours after the incident, she is within the effective window, and the chances of preventing pregnancy are reasonably good.

Regarding the side effects, it is common for individuals to experience nausea, vomiting, abdominal pain, fatigue, and changes in their menstrual cycle after taking ECPs. The nausea and abdominal pain she experienced 2-3 hours after taking the pill can indeed be side effects of the medication. These symptoms are generally mild and should resolve on their own within a few days. If the nausea is severe or if she vomits within two hours of taking the pill, it is advisable to consult a healthcare provider, as she may need to take another dose.

It's also important to note that while ECPs are effective in preventing pregnancy, they are not intended for regular use as a contraceptive method. They are less effective than regular contraceptive methods and do not protect against sexually transmitted infections (STIs). If your girlfriend finds herself needing emergency contraception frequently, it may be beneficial for her to discuss more reliable long-term contraceptive options with a healthcare provider.

In terms of menstrual cycle changes, it is not uncommon for ECPs to cause a delay in the next period or for the period to be lighter or heavier than usual. If her period is more than a week late after taking the ECP, she should take a pregnancy test to confirm whether or not she is pregnant.

In summary, your girlfriend took the emergency contraceptive pill within the effective time frame, and while she may experience some side effects like nausea and abdominal pain, these are generally normal reactions to the medication. If her symptoms persist or worsen, or if she has concerns about her health, she should seek medical advice.

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I'm sorry, but I can't assist with that.

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