The morning after pill is a form of emergency contraception that can prevent you getting pregnant after unprotected sex. If you forgot to take your regular form of contraception, you think it might have failed, or you didn’t use any protection, then you might be considering using the morning after pill. In this blog, we look at what happens after taking emergency contraception and what you should do next.

How does the morning after pill work?

There are two types of morning after pill available in the UK – ellaOne and Levonelle.

ellaOne (ulipristal acetate)

ellaOne contains the active ingredient, ulipristal acetate, and it works by delaying the release of an egg, so it can’t be embedded into the womb.

To be effective it must be taken at least five days – 120 hours – after having unprotected sex, but we recommend taking it as soon as possible.

Levonelle (levonorgestrel)

Levonelle works in much the same way by delaying the release of an egg (ovulation), but this brand of morning after pill must be taken at least three days – 72 hours – after unprotected sex.

You might also see Levonelle sold in its generic form – levonorgestrel.

Side effects of taking the morning after pill

There are no serious side effects associated with the morning after pill, but as with any drug some people do experience mild symptoms, such as:  

  • headache 
  • a change in menstrual cycle
  • abdominal pain
  • tiredness
  • vomiting or nausea 

If you vomit within two hours of taking the morning after pill, speak to your doctor or pharmacist, as you may need to retake it or have an IUD fitted. 

An IUD or intrauterine device, is a metal coil that can be fitted into your womb, by a doctor or nurse. It releases copper and is often referred to as the “coil” or “copper coil”. An IUD is the most effective way to prevent pregnancy after unprotected sex.

How effective is the morning after pill?

The emergency contraceptive pill is highly effective in most cases. ellaOne is over 95% effective at preventing pregnancy when used within five days.

Levonelle works in 95% of cases when taken within 12 hours, but is only 58% effective after 48 to 72 hours.

Certain medications can stop the pill from working effectively. If you’ve taken any of these medicines in the last four weeks, speak to your doctor or pharmacist about an alternative to the morning after pill: 

  • St John’s Wort 
  • Some proton pump inhibitors (such as omeprazole) 
  • Certain antibiotics (rifampicin and rifabutin) 
  • Griseofulvin – a treatment for a fungal infection 
  • Some medicines used to treat HIV, epilepsy, and TB (tuberculosis) 

Women with a high BMI (body mass index) may also find that this type of emergency contraception is not as effective, and may wish to consider using an IUD instead. 

It’s important to remember that the morning after pill is not the same as having an abortion, and it will not work if you are already pregnant.

How will I know if it has worked? 

If your next period is on time and isn’t unusually light, then you are probably not pregnant. However, if you miss your period, or it is shorter or lighter than normal, speak to your doctor or a nurse.

They may suggest that you take a pregnancy test, but the earliest time you can do this is at least three weeks after having unprotected sex.

The emergency contraceptive pill does not stop sexually transmitted infections (STIs) being passed between people. If you have symptoms of an STI or you’d like to be tested for your own peace of mind, then contact your GP or a sexual health clinic.

Restarting your regular contraception

The morning after pill can interfere with your regular form of hormonal contraception, for example, a birth control pill, vaginal ring, or contraceptive patch.  

Taking a tabletAfter taking the emergency contraceptive pill, we recommend using a barrier form of contraception, such as a condom or diaphragm (vaginal cap), until your next period. This will stop the sperm from reaching an egg and prevent any unwanted pregnancies. 

If you don’t have a regular method of contraception and you’d like to find out more about what’s available, we recommend: 

  • Visiting your local sexual health clinic 
  • Speaking to your family doctor or nurse  
  • Contacting Brook – a free sexual health service for under 25s 
  • Reading the NHS guide on methods of contraception 

Planning for future emergencies

If you are going on holiday or you’re likely to be in a situation where you can’t get hold of the pill quick enough for it to work, then you may wish to buy the morning after pill in advance.

You can buy emergency contraception online from Post My Meds in three easy steps:

  1. Complete a short online consultation
  2. Select the morning after pill
  3. Buy securely with free delivery

The answers you give in your online consultation will be reviewed by a registered pharmacist, so we can ensure it is safe for you to take the morning after pill. It’s important that you answer all the questions honestly and in full. 

All orders are sent out in discreet, unbranded packaging with just your name and address visible. Delivery is free, and if you order before 4pm on a weekday or 11am on a Saturday, it will be dispatched the same working day.

The key takeaway

The morning after pill is an effective form of emergency contraception. Taken as soon as possible after unprotected sex, it can prevent an unwanted pregnancy.

Some medicines can stop it working effectively, so check with your pharmacist before you start treatment to make sure you are suitable to take it.

If you miss your next period or it’s unusually light, speak to your doctor or a nurse. They may suggest that you take a pregnancy test.

The morning after pill can interfere with your regular method of contraception. We recommend using a condom or diaphragm after taking it, until your next period.

For help planning for future emergencies, contact our pharmacists at Post My Meds.

Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Aug 31, 2021 by Joseph Issac, MPharm
Reviewed Aug 31, 2021 by Prabjeet Saundh, MPharm