Emergency contraceptive pills should be taken as soon as possible after unprotected sex or contraceptive failure.

Levonorgestrel is generally taken within 72 hours, while ulipristal acetate may be taken within 120 hours. Emergency contraception does not protect against sex that occurs after taking the pill. Take a pregnancy test if your period is significantly delayed or approximately three weeks have passed since unprotected sex.

Sometimes contraception cannot be used in advance or does not work as intended.

In these situations, patients may visit an OB-GYN to receive a prescription for emergency contraception.

When Might Emergency Contraception Be Needed?

Emergency contraception may be considered when:

• A condom breaks or slips off
• Withdrawal was used near the expected time of ovulation
• Sex occurred without contraception
• You cannot remember whether contraception was used
• Sexual intercourse occurred without consent

Some patients visit us after drinking heavily because they cannot clearly remember what happened the night before and want to reduce the possibility of an unintended pregnancy.

Emergency contraception may also be needed after unwanted or non-consensual sexual contact. In this situation, medical care can also help assess possible injuries and the need for STI testing and additional support.

Two Types of Emergency Contraceptive Pills

Emergency contraceptive pills commonly contain either levonorgestrel or ulipristal acetate.

Both medications primarily work by delaying or preventing ovulation. 

They do not terminate an established pregnancy. 

1. Levonorgestrel 1.5 mg

Levonorgestrel emergency contraceptive pills include products such as NorLevo One, Postinor, and Seventwo H.

How It Works

Levonorgestrel primarily delays or prevents ovulation, reducing the chance that an egg will be available for fertilization.

When to Take It

It should generally be taken within 72 hours, or three days, after unprotected intercourse.

The sooner it is taken, the more likely it is to work effectively.

2. EllaOne: Ulipristal Acetate 30 mg

EllaOne contains 30 mg of ulipristal acetate.

How It Works

Ulipristal acetate delays or prevents ovulation. Because ovulation may be delayed, the next menstrual period may also begin later than expected.

When to Take It

EllaOne can be taken within 120 hours, or five days, after unprotected intercourse.

It remains more effective than levonorgestrel between 72 and 120 hours after intercourse. However, it should still be taken as soon as possible. 

Body Weight and Emergency Contraception

The effectiveness of oral emergency contraception may be reduced at a higher body weight or BMI, particularly with levonorgestrel.

Ulipristal acetate may be considered instead, but its effectiveness may also be affected by body weight. Your physician can help determine the most appropriate option based on the time since intercourse, body weight, medical history, and medications currently being used.

The Sooner You Take It, the Better

Regardless of which medication is prescribed, emergency contraception should be taken as soon as possible.

Its effectiveness generally decreases as more time passes after unprotected intercourse. 

Therefore, if you need emergency contraception, do not delay visiting a medical provider.

No emergency contraceptive pill is 100% effective.

Important Precautions After Taking Emergency Contraception

Take a Pregnancy Test If Your Period Is Delayed

Your next period may begin a few days earlier or later than expected after taking emergency contraception.

Take a pregnancy test if:

• Your period is more than approximately one week late
• Your period is unusually light or different
• You develop pregnancy symptoms
• Approximately three weeks have passed since unprotected intercourse

Seek medical care if you experience severe lower abdominal pain, particularly if your period is delayed or a pregnancy test is positive.

It Does Not Protect Future Sexual Intercourse

Emergency contraception only reduces the risk of pregnancy from intercourse that occurred before taking the medication.

It does not continue to protect you from pregnancy if you have unprotected sex afterward.

Use condoms or another reliable contraceptive method for subsequent intercourse.

After taking ulipristal acetate, ask your physician when to begin or resume hormonal contraception, as starting it too soon may reduce the effectiveness of ulipristal.

Repeated Use

Emergency contraception is intended for occasional use rather than as a regular contraceptive method.

Repeated use may cause more menstrual irregularity and uncertainty about the timing of your next period. 

However, the World Health Organization states that repeated use poses no known long-term health risks for most users.

If you need emergency contraception repeatedly, speak with your OB-GYN about a more reliable ongoing method, such as birth control pills, an implant, or an intrauterine device.

What If You Vomit After Taking the Pill?

Nausea and vomiting may occur after taking emergency contraception.

If you vomit within three hours of taking the medication, contact your medical provider because another dose may be needed.

If vomiting occurs after three hours, the medication may already have been absorbed, 

but you should still consult your prescribing clinic if you are uncertain.

Common Side Effects

Possible side effects of emergency contraceptive pills include:

• Headache
• Nausea or vomiting
• Indigestion or abdominal discomfort
• Breast tenderness
• Diarrhea
• Muscle aches
• Fatigue
• Spotting or irregular bleeding
• Changes in menstrual timing or flow

These effects are generally mild and usually resolve without additional treatment. 

If symptoms are severe or persistent, contact your medical provider.

Anyone with an active sex life may unexpectedly need emergency contraception because of contraceptive failure or unprotected intercourse.

The most important point is to take it as soon as possible and understand that it cannot guarantee 100% protection against pregnancy.

Before receiving a prescription, your physician will review the timing of intercourse, your menstrual cycle, the possibility of an existing pregnancy, your current medications, and other relevant health information.

Make sure you understand what to do if you vomit, when to take a pregnancy test, 

and how to prevent pregnancy during subsequent intercourse.

If emergency contraception is needed, do not delay seeking medical advice. 

Proper counseling can help you choose the most appropriate option and use it safely.