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A Word on Language

People use different words to talk about their bodies and their genitals. Here we use medical words—such as penis, anus, and vagina—to describe genitals. Some people use other words, such as private parts, dick, ass and front hole. CATIE acknowledges and respects that people use words that they are most comfortable with.

What is daily PrEP?

PrEP is used by people who are HIV negative to help prevent them from getting HIV. PrEP stands for pre-exposure prophylaxis. It involves taking a prescription pill that contains two medications. It is very important to take the pill every day for it to work.

Taking PrEP also involves seeing a doctor or nurse every three months for HIV testing, screening for other sexually transmitted infections (STIs), monitoring for possible side effects, and ongoing support.

PrEP only helps to prevent HIV—it does not protect against other STIs (such as chlamydia, gonorrhea and syphilis) or other infections (such as hepatitis A, B and C). It also does not prevent pregnancy.

What are some other ways to help prevent HIV and other infections?

PrEP is one of several highly effective ways to help prevent HIV. There are many choices available to you.

Condoms are highly effective at preventing both HIV and other STIs if used consistently and correctly.

When people with HIV take treatment and maintain an undetectable viral load, they do not pass HIV on to their sex partners. Their risk of passing HIV through sharing needles or other injection drug use equipment is also reduced. If you have a partner with HIV who is on treatment and maintaining an undetectable viral load, this is a highly effective strategy to prevent HIV.

Finally, for people who inject drugs, using new injection equipment each time helps to prevent HIV, hepatitis C and other infections.

Who is PrEP for?

PrEP is for people who are at risk for HIV. You might want to use PrEP as a way of staying HIV negative if you:

  • sometimes have vaginal or anal sex without using a condom and you don’t know the current HIV status of one or more of your sex partners
  • have a sex partner who is HIV positive and not on successful treatment
  • use injection drugs and sometimes share needles or other equipment

Talk to your doctor or nurse about whether PrEP is right for you.

How well does PrEP work to prevent HIV transmission?

For people who take PrEP as prescribed and who have regular ongoing medical care, it is rare to get HIV through sex. Taking PrEP as prescribed also dramatically lowers the risk of getting HIV from sharing needles to inject drugs.

Taking your pills as prescribed is very important because PrEP can be less effective when pills are missed. If pills are missed, drug levels in your body may be too low to prevent HIV infection.

Is PrEP safe?

PrEP is generally safe and well tolerated, and most people who take it report no side effects. Some people experience side effects such as nausea, diarrhea or fatigue, but these usually go away on their own within a few days to weeks as the body adjusts to the medication.

Talk to your doctor, nurse or pharmacist if you experience any side effects from PrEP.

For some people, PrEP can affect the kidneys, liver and bones. If this happens, organ function and bone density usually return to normal after PrEP is stopped. Your doctor should monitor your kidney function while you are taking PrEP and check for other potential drug effects on the body.

What is involved in taking PrEP besides taking pills?

Being on PrEP involves more than just taking pills.

Before starting PrEP it is important to be tested to make sure you don’t already have HIV. Starting PrEP if you are HIV positive (but don’t know it) can create serious problems for future HIV treatment.

Before starting PrEP you will need to have your kidney function tested, and you should also be tested for other STIs and hepatitis A, B and C.

You will need to see a doctor or nurse after your first month on PrEP and every three months after that to test for HIV and other STIs, monitor for side effects and get ongoing support if you need it. If there is a chance that you could be pregnant, your doctor can also do a pregnancy test at each visit.

Are there other types of PrEP?

For gay men and other men who have sex with men there is an option to take on-demand PrEP. On-demand PrEP means taking pills only on days before and after having sex. This could be a good option for men who know in advance when they will have sex. It involves taking two pills 2 to 24 hours before sex, one pill 24 hours after the first dose, and another pill 24 hours after that. If a person has sex several days in a row, they should continue to take a pill every 24 hours until two days after the last time they have sex.

For women and trans guys who have vaginal (frontal) sex, it is very important to take PrEP every day and not miss any pills because daily dosing is needed to keep drug levels high in the vagina.

Can trans people take daily PrEP?

Daily PrEP can be used by people of all genders. Experts believe that PrEP can effectively prevent HIV in trans people and that the drugs in PrEP are unlikely to interfere with the hormones that some trans people take; however, this has not been well studied. There is currently no evidence showing how well PrEP works for people who have undergone gender-affirming surgeries.

Can daily PrEP be used by people who are pregnant, breastfeeding or planning to have a baby?

Daily PrEP is safe to take while pregnant and breastfeeding, for both the parent and the baby. PrEP may also be an HIV prevention option for couples who want to have a baby if one partner is HIV positive and not on successful treatment. Talk to your doctor if you are pregnant, breastfeeding or planning to have a baby.

How can I remember to take my pills and go to doctor’s appointments?

Some people find it hard to remember to take a pill every day and to go to doctor’s appointments regularly, but there are tools that can help with this.

If you think you might have difficulty following the PrEP regimen, you can talk to your doctor or pharmacist or contact an HIV organization for help developing a strategy that will work for you.

What are some other benefits of PrEP?

PrEP has benefits beyond preventing HIV.

If you worry about getting HIV, being on PrEP can help you feel less anxious about this.

PrEP is a way to help prevent HIV that you can control without other people knowing that you are using it.

You can be on PrEP for as long or as short a time as you want. Many people only use PrEP for a period in their life when they need it, based on their risk for HIV at the time. If you want to stop taking PrEP, or restart after a period of not taking PrEP, talk to your healthcare provider about how to stop and/or restart PrEP safely.

How can I get PrEP?

If you want to take PrEP, you have to talk to a medical professional. Any doctor can prescribe PrEP and some nurses are also licensed to prescribe it.

PrEP medications can be expensive, but cheaper generic versions exist. PrEP is covered by some private and public health insurance plans in Canada.

You may want to contact your doctor, a pharmacist, a sexual health clinic or an HIV organization to learn about ways to cover the cost of PrEP.


Writer: Mallory Harrigan

Design: GravityInc.ca

CATIE thanks AIDS Vancouver Island, Saskatoon Sexual Health, and Women and HIV/AIDS Initiative (Ontario) for reviewing this resource. We also thank Dr. Isaac Bogoch, Toronto General Hospital Research Institute, for medical review.