What is PrEP?

  • PrEP stands for pre-exposure prophylaxis.
  • Oral PrEP is a pill taken before sex to protect you from HIV, so it is pre-exposure. Prophylaxis means to prevent infection.
  • It is extremely effective when taken properly.
  • Oral Pre-exposure prophylaxis (PrEP) is usually a one pill regime containing a combination of 2 anti-HIV medications (Emtricitabine and Tenofovir).
  • PrEP should only be prescribed to HIV negative patients.

When should PrEP ideally taken?
PrEP is ideal for you if you are HIV negative and have increased risk of getting HIV, including situations when condoms are not easily accessible or not used. PrEP is a way to stay HIV negative and protect yourself.

Who should take PrEP?

  • PrEP is recommended for individuals who:
    • Have been diagnosed with STIs in the past 6 months.
    • Are not in a mutually monogamous relationship with a partner.
    • Have recently needed PEPse (post-exposure prophylaxis for sexual encounter).
    • Are gay men or bisexual men who have had anal sex without using a condom.
    • Are heterosexual men or women who do not regularly use condoms during sex with partners of unknown HIV status.
    • Inject drugs for recreational use.
    • Use recreational drugs for chemsex (for example: crystal meth, mephadrone and GHB).
    • Have an HIV positive partner who is finding it difficult to take their HIV meds regularly.
    • Are sex workers.
    • Have a current sexual partner or partners who are living with HIV and have a high level of the HIV virus in their body (sometimes called a detectable viral load).

Does PrEP protect you from STIs?

  • No, PrEP only protects you against HIV. You need to take other precautions if you want to reduce the risk of contracting other sexually transmitted infections (STIs) such as Gonorrhea, Chlamydia, Syphilis and Hepatitis C.
  • Other infections such as Chlamydia, Gonorrhoea, Trichomoniasis, Syphilis, Hepatitis A,B & C, Genital Warts (HPV) and Mycoplasma are still transmissible.
  • Even if you are on PrEP you may need to use adequate protection methods (including condoms) if you want to be protected from other infections.

How should I start PrEP?

Just before starting PrEP, you will need to take an HIV test.

Ideally, you should also take:

  • A complete sexually transmitted infection screening. We recommend a full STI screen every 3 months, even if you do not have any symptoms.
  • A blood test to check your kidney function. In a very small number of people PrEP can damage renal (kidney) function. This is rare and usually only in people with existing kidney problems or who take other medication that may affect the kidneys.

How do you take PrEP?
Event-driven (On Demand) dosing works if you plan or know when you will be having sex. Event-based dosing is when you take PrEP pills before and after each episode of sexual activity.

Event-based dosing should only be used if your only risk of getting HIV is from sexual exposure and you were assigned male at birth.

Daily (Continuous) dosing means you take a (1) one tablet every day. Taking PrEP every day ensures protective levels of PrEP in your body 24 hours a day, seven days a week. This is a better choice for those who are more likely to have unplanned sex or cannot predict when sex is likely to occur, daily dosing provides the best protection. If you are not eligible for event-driven PrEP you will be protected once you have taken the 7-day course of PrEP pills prior to potential exposure.

It is very important to speak to a GU specialist to help you choose the best way to take PrEP.

PrEP Event-driven*ED (On Demand)
It is important not to miss any doses.

  • Individuals eligible for ED-PrEP, can start oral PrEP by taking two doses 2-24 hours prior to potential sexual exposure (ideally closer to 24 hours). Regardless of whether they intend to use an oral daily (continuous) or ED-PrEP dosing regimen (On Demand) and continue to take one dose per day until two days after the day of the last potential sexual exposure they should:
    • Take 2 pills: 2-24 hours before sex.
    • Sex-free day: Take 1 pill 24 hours after sexual exposure.
    • Sex-free day: Take 1 more pill 24 hours after that:
  • If you’re having sex for an extended period of time, perhaps over a few days or a weekend, continue to take a pill every 24 hours until you have 2 sex-free days.
  • These individuals are eligible to start PrEP Event-driven PrEP (on Demand):
    • Assigned male at birth regardless of sexual orientation or gender identity/diversity who
    • Have sexual exposure AND
    • Are not taking gender-affirming hormonal therapy (exogenous estradiol-based hormones).

PrEP-Daily (Continuous)

  • Daily PrEP for 7 days before the first potential exposure.
  • Daily PrEP is best taken at the same time each day, so it becomes part of your routine, but a few hours late or early is fine.
  • Starting PrEP using this method requires starting a regime of 1 pill once daily for a minimum of 7 days prior to any sexual activity. One must then continue taking 1 pill once daily.
  • If you want to STOP PrEP, you can stop taking daily PrEP seven days after the last potential exposure.
  • These individuals are eligible to start daily oral PrEP:
    • Assigned female at birth regardless of sexual orientation or gender identity / diversity.
    • Assigned male at birth regardless of sexual orientation or gender identity / diversity who are taking gender-affirming hormonal therapy (exogenous estradiol-based hormones).
    • People who inject drugs.

Reference List:

World Health Organization. (‎2022)‎. Differentiated and simplified pre-exposure prophylaxis for HIV prevention: update to WHO implementation guidance: technical brief. World Health Organization. License: CC BY-NC-SA 3.0 IGO