What is PrEP

Oral PrEP involves the use of antiretroviral drugs by an HIV-negative person to reduce their risk of getting HIV. Oral PrEP is taken in pill form, starting before being exposed to HIV and continuing afterwards. The daily use of oral PrEP has been approved by Health Canada. When oral PrEP is taken consistently and correctly, antiretroviral drugs get into the bloodstream and genital and rectal tissues. The drugs work to help prevent HIV from replicating within the body’s immune cells, which helps to prevent a permanent infection. Evidence from RCTs suggests that daily oral PrEP is equally effective for vaginal and anal sex when used consistently and correctly. There is some evidence showing that the drugs in PrEP take longer to reach maximum levels in vaginal tissues compared to rectal tissues.

Some of the possible side effects include:

  • nausea
  • vomiting
  • diarrhea
  • headache
  • dizziness


In clinical trials, these side effects were generally mild, temporary, and only affected between 1% and 10% of participants. PrEP may also cause small decreases in kidney, liver and bone health. These changes were reversible after stopping PrEP.

An HIV-negative person who wants to take PrEP needs to get a prescription from a doctor. 

Oral PrEP can cost between $250 and $1000 a month. Currently, only some private and public health insurance plans in Canada will cover the cost of the drugs. Advocacy is needed to get PrEP covered by all provincial, territorial and federal drug programs to ensure that people who need PrEP can access it.