About PrEP

What is PrEP?

PrEP, or Pre-Exposure Prophylaxis, is a highly effective way for people at high risk to have more control over their sex lives and protect themselves from HIV.

PrEP involves taking one pill a day. The medication prevents the human immunodeficiency virus (HIV) from multiplying which means that, if you are exposed to HIV, PrEP makes it very difficult for the virus to infect your body.

When taken daily, PrEP can significantly reduce the risk of acquiring HIV.

PrEP works to prevent HIV but it doesn’t protect you against other sexually transmitted infections (STIs) or prevent pregnancy. Therefore, people using PrEP should also take other steps to protect their sexual health, including regular STI testing.


How do we know PrEP works?

Clinical trials have shown that PrEP works when it’s taken correctly and consistently.

The small number of people who have become infected with HIV while using PrEP were not taking it every day.

PrEP only works if you have enough of the medication in your body, so you need to take PrEP every day.


How long do I have to take PrEP for it to start protecting me?

The number of days you have to take PrEP to establish the right levels of drug in your body varies. For people having anal sex, we recommend 7 days. For people having vaginal or front hole sex and for people who inject drugs, we recommend 21 days.


Is PrEP safe? What are the side effects?

PrEP is safe. The drugs used for PrEP have been part of safe, effective HIV treatments since 2004.

Most people taking PrEP have no side effects. For those who do, the most common ones are nausea, upset stomach, fatigue and headaches. These symptoms often go away within a month of starting PrEP.

In rare cases, PrEP can cause kidney or bone problems. That’s why anyone taking PrEP should see their health care provider every three months to be monitored for any signs of these problems.


Is PrEP right for me?

PrEP is only one way to prevent HIV and improve your sexual health – and it’s not right for everyone.

PrEP may be right for you if you are:

  • A man who has condomless anal sex with other men and has any of the following risk factors:
    • rectal gonorrhoea or other sexually transmitted infections (STIs) of the rectum
    • infectious syphilis
    • has had more than one course of PEP (post-exposure prophylaxis)
    • an HIV-positive partner who does not have a suppressed viral load
    • a partner(s) whose HIV status is unknown
    • a high score on a valid HIV risk assessment tool
    • used methamphetamines such as crystal or speed in the past 6 months
    • injects drugs and sometimes share needles
  • A transgender woman who has condomless anal sex and any of the following risk factors:
    • rectal gonorrhoea or other sexually transmitted infections (STIs) of the rectum
    • infectious syphilis
    • has had more than one course of PEP (post-exposure prophylaxis)
    • an HIV-positive partner who does not have a suppressed viral load
    • a high score on a valid HIV risk assessment tool
    • used methamphetamines such as crystal or speed in the past 6 months
    • injects drugs and sometimes share needles
  • A heterosexual man or woman who:
    • has condomless anal or vaginal sex with an HIV-positive partner who does not have a suppressed viral load
    • has condomless anal or vaginal sex with a partner(s) whose HIV status is unknown
    • has condomless anal or vaginal sex with a partner who injects drugs
    • has had infectious syphilis
    • has had more than one course of PEP (post-exposure prophylaxis)
    • injects drugs and sometimes share needles

Use the private, Risk Assessment tool on this website to see if PrEP might be right for you.


Interested in PrEP?

Answer a few questions to find out if PrEP would be a good way to improve your sexual health. Then talk to a health care provider so you have all the information you need to decide whether PrEP or another form of HIV prevention is right for you. Use our Clinic Finder tool to find a PrEP provider in your area.

More FAQs

Yes, PrEP can be an effective form of HIV prevention for women.

PrEP is not a birth control option – it doesn’t prevent pregnancy. However, it is safe to use with all forms of birth control including oral contraceptives, IUDs and condoms.

Yes, PrEP is safe for pregnant women or women trying to conceive. There isn’t a lot of research on using PrEP during pregnancy and breast feeding/chest feeding but there is a lot of research that shows it’s safe for pregnant women to use the same drugs for HIV treatment. If you have questions about using PrEP during pregnancy or while breast feeding/chest feeding, talk to your doctor.

Yes, PrEP can be an effective way for trans and gender diverse people to take some of the worry out of sex and prevent HIV. PrEP is safe to take with different types of hormone therapy.

Research on using PrEP after gender affirming surgery is limited. Most guidelines suggest that trans people who have had gender affirming surgeries should wait 21 days for PrEP to be effective for front hole sex.

PrEP is safe to take if you are using recreational or street drugs, and it can be a good way to prevent HIV if you sometimes share needles.

PrEP will protect you from HIV but it will not protect you from other STIs or from getting pregnant. Using PrEP and condoms together is good for your sexual health.