What is PrEP?
PrEP stands for pre-exposure prophylaxis. It is medication used by people who are HIV negative to help prevent getting HIV.
There are a few different types of medication that can be used as PrEP. Most people who use PrEP take pills. A long-acting version of PrEP is also available by injection. It is very important to take PrEP as prescribed for it to work.
Taking PrEP involves seeing a healthcare provider regularly. Visits will include HIV testing, screening for other sexually transmitted infections (STIs), monitoring for possible side effects, and ongoing support.
Note: In this resource we refer to transgender (trans) and cisgender (cis) people. Trans people are people whose gender identity and/or expression is different from the sex they were assigned at birth, and cis people are people whose gender is the same as the sex they were assigned at birth.
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 sex without using a condom and you don’t know the HIV status of one or more of your sex partners
- have a sex partner who is living with HIV and not on successful treatment
- inject drugs and sometimes share needles or other injecting equipment
Talk to a healthcare provider about whether PrEP is right for you.
What types of PrEP are available?
PrEP is available in pill form or by injection from a healthcare provider.
There are two possible ways to take PrEP in pill form. One way is to take a pill every day. Anyone who may be at risk for HIV through sex or from sharing equipment for injecting drugs can consider taking PrEP as a daily pill.
Another option is to take PrEP only on days before and after having sex. This approach can be used to prevent getting HIV through sex by gay, bisexual and other men who have sex with men; trans women; and cis heterosexual men. It is sometimes called PrEP 2-1-1 or on-demand PrEP. PrEP 2-1-1 refers to the dosing schedule, which involves taking 2 pills between 2 and 24 hours before sex, 1 pill 24 hours after the first dose and 1 more pill another 24 hours later. 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. PrEP 2-1-1 is not recommended for cis women or trans men. It is also not recommended for anyone who may be at risk for HIV through sharing equipment for injecting drugs.
Another PrEP option is long-acting injectable PrEP. Taking injectable PrEP involves getting an injection from a healthcare provider once per month for the first two months and then every two months after that. Anyone who may be at risk for HIV through sex can consider taking injectable PrEP, but it is not recommended for people who may be at risk for HIV through sharing equipment to inject drugs.
How well does PrEP work to prevent HIV transmission?
It is rare for people who take PrEP as prescribed to get HIV. Taking PrEP as prescribed is very important for it to work. If pills or injections are missed or not taken on schedule, medication levels in your body may be too low to prevent HIV.
If you think it might be challenging for you to take pills as prescribed or to keep up with appointments, reminder tools are available to support you. Talk to a healthcare provider or to someone at an HIV organization to find a strategy that will work for you.
Keep in mind that PrEP only prevents HIV. It doesn’t prevent other STIs, such as syphilis, chlamydia and gonorrhea, or other infections such as hepatitis A, B or C. Using condoms during sex lowers the chance of passing all STIs, and using all new equipment for injecting drugs prevents passing blood-borne infections.
What is involved in taking PrEP besides taking medication?
Being on PrEP involves more than just taking pills or getting injections.
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. You should also be tested for other STIs and blood-borne infections.
Depending on what type of PrEP you would like to take, your healthcare provider might also do some other tests to make sure it’s right for you.
Once you start PrEP you will need to see a healthcare provider regularly, usually one month after you start and every three months after that. At these visits, you will get tested for HIV and other STIs and blood-borne infections, and your healthcare provider will monitor for any possible drug side effects. These visits are also an opportunity to get ongoing support if you need it.
Is PrEP safe?
PrEP is generally safe and well tolerated. Most people who take PrEP in pill form report no side effects. For those who do, side effects may include nausea, diarrhea or fatigue, and they usually go away on their own within a few days or weeks as the body adjusts to the medication. The most common side effect for people who get PrEP injections is tenderness in the injection site, but this also tends to decrease after the first few injections. Severe side effects from PrEP are extremely rare.
Before you start taking PrEP, your healthcare provider will ask you about any other medications that you take and any health conditions that you have. Based on this, they will let you know what type(s) of PrEP you can consider taking.
If you are trans or non-binary, make sure to tell your healthcare provider if you are taking gender-affirming hormones or have had gender-affirming bottom surgery, or if you are considering doing so in the future. These factors might affect the types of PrEP that you can consider. Experts do not think that PrEP makes gender-affirming hormone therapies less effective.
Tell your healthcare provider if you are pregnant, breastfeeding (chestfeeding) or planning to get pregnant. They can let you know what type of PrEP is safe and appropriate for you.
Can I stop taking PrEP or switch to a different type of PrEP?
Yes, you can stop taking PrEP if you no longer want to be on it. Many people only use PrEP for a period in their life when they need it, based on their risk for HIV at the time. After you start taking PrEP you might want to switch to a different kind of PrEP. For example, if you are having trouble remembering to take pills, you might want to switch to long-acting injectable PrEP.
Talk to a healthcare provider if you want to stop taking PrEP or restart after a period of not taking it, or if you are considering switching to a different type of PrEP. They will tell you how to do so safely.
How can I get PrEP?
If you want to take PrEP, you have to get a prescription from a healthcare provider. A doctor or nurse practitioner can prescribe PrEP. In some regions, other healthcare providers such as pharmacists may also be able to prescribe it.
PrEP medications can be expensive, but the cost may be covered by some private and public health insurance plans. You may want to contact a doctor, a pharmacist, a sexual health clinic or an HIV organization to learn about ways to cover the cost of PrEP.
Visit whereto.catie.ca to find PrEP providers and other services near you.