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Long-Term Effects of Emergency Contraceptive Pill On The Menstrual Cycle

Emergency contraceptive pill (ECP) has become a critical component of reproductive health, offering a backup option for preventing an unintended pregnancy. However, amidst their widespread use, concerns about their impact on the menstrual cycle, especially in the long term, persist. This blog delves into the possible effects of an ECP on the menstrual cycle, backed by peer-reviewed research.

How Does An Emergency Contraceptive Pill Work

An emergency contraceptive pill (ECP), often referred to as the morning-after pill or plan B, is designed to prevent pregnancy after unprotected sex (when no contraception is used) or contraceptive failure (for example, when the condom breaks, slips, or leaks during sex). It works primarily by preventing or delaying ovulation and is not effective if a pregnancy has already begun.

In India, the single pill containing Levonorgestrel (LNG) is most commonly used. It should be taken as soon as possible within 72 hours after unprotected sex or contraceptive failure.

how does a emergency contraceptive pill or ecp or morning after pill or plan b or ipill or unwanted 72 pill works

Short-Term Effects On The Menstrual Cycle

Period Timing and Duration

The immediate effect of taking an emergency contraceptive pill (ECP) can include changes in timing and duration of the next period. Some women may experience their next period up to a week earlier or later than expected, and it may be slightly longer than usual.

Period Flow and Spotting

Change in flow is also common. Some women may have their next period slightly lighter or heavier than usual. Some spotting between ECP use and the next period is also possible. This light bleeding is sometimes confusing and a concern, but it is generally not indicative of a serious issue.

Other symptoms

Some women may experience increased or decreased menstrual cramps during their next period. Other symptoms such as nausea, headache, fatigue, and breast tenderness, are also possible.

These effects are generally short-lived and do not indicate any long-term health issues.

possible effects of an emergency contraceptive pill or ecp or morning after pill or plan b or ipill or unwanted 72 pill on periods

Long-Term Effects On The Menstrual Cycle

Concerns about long-term effects on the menstrual cycle often arise. Research indicates that while an ECP can cause temporary changes in the menstrual cycle, there is no substantial evidence to suggest long-term negative effects on the menstrual cycle if used as directed. It is important to note that frequent use of ECP as a regular birth control method is not recommended, and reliance on ECP over regular contraceptive methods is not advised.

long term effects of emergency contraceptive pill or morning after pill or plan b or ipill or unwanted 72 on the menstrual cycle

When To Consult A Doctor

If you experience significant changes in your menstrual cycle, such as severe pain, extremely heavy bleeding, or if your period is delayed for more than a week, it's crucial to consult a doctor. These symptoms can occasionally indicate other underlying health issues that require attention.


Emergency contraceptive pill (ECP) offers a valuable option for preventing unintended pregnancies. While it can cause temporary changes in the menstrual cycle, evidence suggests these effects are not long-term. It is essential to use it responsibly and consult doctors for any concerns or if you're experiencing significant menstrual changes after use.


This blog, including its text, images, and infographics, are for educational purposes only and not a substitute for professional medical advice. For personalized advice, always consult a doctor.

Further Reading 

For more details on this or related topics, refer to the papers listed in References below, the FAQs on the ECP page, or other blogs on the Learn page of our website


  • Family Planning Division, Ministry of Health and Family Welfare Government of India. Guidelines for Administration of Emergency Contraceptive Pills by Health Care Providers. 2008.

  • Contraception. Menstrual bleeding patterns following levonorgestrel emergency contraception. 2006.

  • World Health Organization (WHO). Emergency Contraception. 2021.


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