Emergency Contraception: Morning-After Pill and Its Side Effects

Attitudes towards sex have become more open in modern society, and sexual health is now widely recognised as an important part of overall wellbeing. Although most people understand the importance of practising safe sex, there are times when contraception is forgotten in the heat of the moment, or when measures fail, for example if a condom breaks or slips off. In these situations, the emergency contraceptive pill (commonly known as the morning-after pill) offers a way to help prevent an unintended pregnancy. While the morning-after pill is a common and effective method of emergency contraception, many people still have questions about its side effects and how it affects the body. This article provides a comprehensive overview of how the morning-after pill works and its potential side effects.

What is the morning-after pill?

The morning-after pill is a medication used for emergency contraception after sexual intercourse. There are two main types: a single-hormone pill containing levonorgestrel, and a pill containing the progesterone receptor modulator ulipristal acetate. These medications work primarily by delaying ovulation, preventing sperm from fertilising an egg, or altering the uterine lining to prevent a fertilised egg from implanting.

Types of morning-after pill

There are different types and brands of morning-after pill. The table below compares the two main options:

	Single-hormone (progesterone / levonorgestrel)	Progesterone receptor modulator
Brand names	Plan B One-Step, Take Action, etc.	Ella
Time window	Within 72 hours	Best within 120 hours
Single dose	1.5 mg	30 mg
How it works	Raises progesterone levels in the body, suppressing the hypothalamus from releasing hormones that trigger ovulation, thereby delaying it.	Binds to progesterone receptors in the body, producing an effect that suppresses or delays ovulation.
Side effects	Nausea, headache, fatigue, menstrual changes, lower abdominal pain, breast tenderness, irregular bleeding
Failure rate	2-3%	1-2%
How to obtain	In Hong Kong, both types of emergency contraceptive pill are prescription-only medications. A valid prescription from a registered doctor is required. Consult your doctor before use.

How effective is the morning-after pill?

The morning-after pill is a highly effective method of emergency contraception. When taken as directed, it can be up to 95% effective. However, its effectiveness decreases over time, so it is important to take it as soon as possible after unprotected intercourse or uncertainty of protection.

When to take the morning-after pill?

The morning-after pill should be taken as soon as possible after unprotected sex. Most morning-after pills are most effective when taken within 72 hours of intercourse, although certain formulations (such as those containing ulipristal acetate) can be taken up to 120 hours afterwards.

Side effects of the morning-after pill

The side effects of the morning-after pill are usually short-lived and may include:

Headache and fatigue: These are common, mild side effects after taking the morning-after pill.
Nausea and vomiting: Some users may experience digestive discomfort. If vomiting occurs within two hours of taking the pill, a second dose may be needed.
Changes to your period: The morning-after pill may cause your next period to arrive earlier or later than expected, and may alter the menstrual flow.
Mood swings and breast tenderness: Hormonal changes can cause mood fluctuations or mild breast tenderness.
Abdominal pain or discomfort: Some women may experience lower abdominal pain or discomfort after taking the morning-after pill.

Is the morning-after pill harmful? What are the long-term effects?

There is currently no evidence that the morning-after pill causes long-term harm to fertility. However, it is designed for occasional use and is not suitable as a regular method of contraception. Frequent use of morning-after pills may lead to irregular menstrual cycles, so it is advisable to consult your doctor about finding a regular contraceptive method that suits you.

Morning-after pill Q&A

1. Is the morning-after pill the same as an abortion pill?

No. The morning-after pill is not an abortion pill. It works by preventing ovulation or fertilisation, or by preventing a fertilised egg from implanting. It does not terminate an existing pregnancy.

2. Will taking the morning-after pill affect future fertility?

There is currently no evidence that the morning-after pill affects long-term fertility. Its effects on the body are temporary.

3. Can the morning-after pill replace regular contraception?

No. The morning-after pill is an emergency measure only and should not be used as a routine method of contraception. Regular contraceptive options, such as the oral contraceptive pill, condoms, intrauterine devices (IUDs), vasectomy or tubal ligation, are more effective and safer for ongoing use.

Conclusion

The morning-after pill is one option for emergency contraception, providing a backup when regular contraception fails or no precautions are taken. However, it does come with side effects and is not a substitute for regular contraception. Emergency contraceptive pills should only be used in urgent situations and are best taken within 72 hours of unprotected sex. If you are unsure which long-term contraceptive method is right for you, please book an appointment with one of our family doctors for professional medical advice.