Patient information from BMJ

HIV: prevention treatment (PrEP)

Last published:Nov 16, 2023

If you are at high risk of being infected with HIV - for example, if your partner has HIV - your doctor might suggest that you take some drugs (called PrEP) to protect against infection with the virus. 

HIV stands for Human Immunodeficiency Virus. If you are infected with HIV, it can damage your immune system. This makes it harder to fight off some types of infection, and easier for some cancers to develop. 

Without treatment, HIV infection can lead to AIDS. AIDS stands for Acquired Immune Deficiency Syndrome.

The treatment for HIV is called antiretroviral treatment, or ART for short. People with HIV who are being treated with ART take these drugs every day, for the rest of their lives.

What is PrEP?

Many people who don’t have HIV also take a type of ART called PrEP.

PrEP stands for pre-exposure prophylaxis. Prophylaxis is another word for prevention.

If you are at high risk of being infected with HIV, taking PrEP reduces your chances of being infected.

Reasons why someone might be at high risk of HIV infection and require PrEP include being sexually active (vaginal or anal sex) and:

• having a partner with HIV

• having a recent infection from sex

• being someone who injects recreational 'street' drugs, such as heroin, or having a partner with HIV who does

• not using condoms with people you are not sure have or don’t have HIV.

How do I take PrEP?

If you take PrEP, you will usually take one tablet every day. For it to work properly you have to take it regularly, as prescribed, without missing doses. In some countries, you may be offered an injection of PrEP instead. This may be better for you if you struggle to take tablets every day.

Some men who have sex with men might be able to take PrEP in a more as-needed or 'on demand' way, usually if they only have sex with men occasionally. But this type of prescribing might not be available everywhere.

Ask your doctor about how PrEP is available where you live.

Is PrEP right for me?

PrEP has helped to reduce the spread of HIV. But it shouldn’t lead to people becoming less careful. For example, research suggests that men who take PrEP might be less likely to use condoms.

Using a condom can still be the safest way to have sex. This is partly because, while PrEP can protect against HIV in many people, it doesn’t protect against other sexually transmitted diseases.

PrEP is still hugely helpful in preventing the spread of HIV. But it’s not possible to say whether it will work for you as an individual. 

If you think you are at high risk of HIV infection for any reason, or if you want to learn more about PrEP, talk to your doctor.