Almost all methods of contraception can occasionally fail. If you think yours has, there’s no need to panic as there are still steps you can take to help prevent an unwanted pregnancy

How is contraceptive effectiveness measured?


A contraceptive's effectiveness will always be expressed as a percentage. A success rate of 98 percent means that, out of all the women using that method for one year, two in 100 will still get pregnant. 


Many methods measure 'perfect use' (when the method is used with no mistakes) and 'typical use' (which includes situations such as occasionally forgetting to take a pill, or incorrect condom use).


Contraceptive pill effectiveness


There are two types of contraceptive pill: the combined contraceptive pill, and the progesterone-only or 'mini' pill. For both, the 'perfect use' success rate is greater than 99 percent, whereas the 'typical use' success rate is 91 percent – so around nine in 100 women will get pregnant while using the pill for one year.


The most common reasons for contraceptive pill failure are:


• Forgetting to take your pill

• Not taking your pill promptly. You should take your pill at around the same time every day

• Having an episode of vomiting or diarrhoea. This can mean your body doesn't absorb your pill properly

• Taking a medicine which is known to make the pill less effective. This information will be listed in the patient information leaflet inside your medicine box


If you have any questions about taking your pill, talk to your pharmacist or GP.


We offer both types of contraceptive pill via our Online Doctor – Contraceptive Pill Service.* A clinician will talk through the options and success rates with you in more detail.


Condom effectiveness


The 'perfect use' success rate for male condoms is 98 percent – the 'typical use' success rate is 82 percent. So around 18 in 100 women each year get pregnant while using male condoms. For female condoms, the 'perfect use' success rate is 95 percent and the 'typical' use success rate is 79 percent - so around 21 women in 100 women each year get pregnant while using female condoms. 


The most common reasons for failure are:


• Damage to the condom – such as small tears from fingernails or jewellery

• Not putting the condom on early enough. Small quantities of sperm can be present even before the man ejaculates, so you should put on the condom before the penis touches the vagina

• Not pulling out immediately after sex. To prevent the condom coming off inside the woman, the man should pull out while the penis is still erect, holding the condom in place

• Using an oil-based lubricant. This can cause the condom to split or tear. Check the labels on both lubricants and condoms, and ask your pharmacist for advice if you're unsure


Long-acting reversible contraceptives (LARCs)


This includes intrauterine devices (IUDs) fitted into the uterus, and contraceptive implants placed just under the skin. 


IUD effectiveness


The 'perfect use' success rate for IUDs is greater than 99 percent. There's no 'typical use' rate because there's nothing further the user needs to do or to remember to make this method successful.


When your IUD is fitted, your nurse or doctor will show you how to check for the two small threads at the top of your vagina. If you can't find these threads, your IUD may have become dislodged.


Contraceptive implant effectiveness


The 'perfect use' success rate for the contraceptive implant is also greater than 99 percent. Again, there's no 'typical use' rate because there's nothing further the user needs to do or to remember to make this method successful.


Some medicines are known to make your contraceptive implant temporarily less effective. This will be clearly listed in the patient information leaflet inside the medicine. If you're not sure, talk to your GP or pharmacist.


What to do if you think your contraception has failed


If your contraception has failed, or if you didn't use contraception, there are still steps you can take to help prevent an unwanted pregnancy. 


These methods are more effective the sooner they are used, so it's important to act quickly.


The emergency contraceptive ('morning after') pill


Although it's often called the 'morning after' pill, you can take the emergency contraceptive pill up to five days after unprotected sex. However, the sooner you take it, the more effective it is. 


You can get the emergency contraceptive pill from your pharmacist, following a private chat with them (subject to eligibility criteria and pharmacist availability). Some pharmacies are open until midnight from Monday to Saturday. You can find your nearest Boots pharmacy by visiting www.boots.com/store-locator and putting in your postcode.


You can also access the morning after pill from your GP, family planning clinic or via our Online Doctor – Morning After Pill Service where a clinician will chat through the process in more detail.*


The emergency contraceptive pill doesn't provide ongoing protection. You still need to use contraception when you next have sex. Speak to your GP or family planning clinic for advice on regular contraception.


Emergency IUD fitting


Having an intrauterine device (or IUD) fitted is the most reliable way to prevent pregnancy after unprotected sex. Less than one percent of women become pregnant after having an emergency IUD fitted. 


An emergency IUD can be fitted up to five days after unprotected sex. See your GP or practice nurse, or visit a sexual health clinic. You can keep your IUD in place to provide contraceptive protection for the future. If you'd prefer to have it removed, see your GP or visit a sexual health clinic.


What to do after using emergency contraception


If your period is more than five days late, you experience light or unusually heavy bleeding or if you think you may be pregnant, you should take a pregnancy test. You should see your doctor if you find out you’re pregnant.


If you didn’t use a condom or have experienced condom failure during intercourse, you may be at risk of developing a sexually transmitted disease. If you’re worried, visit a sexual health clinic to check for STIs. You can also talk to your GP or pharmacist for advice.


Next steps


• The emergency contraceptive pill can be taken up to five days after having unprotected sex, but it's more effective the sooner it's taken, so don't wait

• If you didn’t use a condom or have experienced condom failure, you may want to visit your sexual health clinic for an STI check-up

*Subject to availability and clinician approval. Charges apply