# PrEP ## Understanding PrEP
What is PrEP and how does it help prevent HIV? PrEP (Pre-Exposure Prophylaxis) is a medication that helps prevent HIV before exposure to the virus. It’s taken by people who are at risk of getting HIV, such as those with HIV-positive partners, individuals who have multiple sexual partners, or people who inject drugs. PrEP works by using antiretroviral drugs that stop HIV from multiplying in the body, preventing infection if someone is exposed to the virus.
How well does PrEP work at preventing HIV? PrEP is highly effective when taken as prescribed: * **Daily PrEP** reduces the risk of getting HIV from sex by **99%** and from injection drug use by **at least 74%**. * **On-demand PrEP** (taking pills around the time of sex) has been shown to be about **86-97% effective** for men who have sex with men. * Effectiveness drops if PrEP is not taken consistently, so it’s important to follow the recommended schedule. Reference:
How is PrEP different from PEP (Post-Exposure Prophylaxis)? PrEP and PEP are both used to prevent HIV but in different situations: * **PrEP** is taken **before** exposure to HIV, on an ongoing basis, by people who are at continued risk. * **PEP** (Post-Exposure Prophylaxis) is taken **after** a possible HIV exposure (e.g., unprotected sex, sharing needles) and must be started **within 72 hours** of exposure. PEP is taken for 28 days and is an emergency treatment, while PrEP is for regular prevention
Who should consider taking PrEP? PrEP is recommended for anyone at high risk of HIV, including: * People with an HIV-positive partner (especially if their partner is not on treatment). * Gay, bisexual, and other men who have sex with men, particularly those who don’t always use condoms. * People who have multiple sexual partners or partners whose HIV status is unknown. * Sex workers who may have clients with unknown HIV status. * People who inject drugs and share needles. * People who have recently used PEP multiple times. If you think you might be at risk, a TeleTest physician can help determine if PrEP is right for you. Reference:
How does PrEP fit into a complete HIV prevention plan? PrEP is one part of a broader strategy to prevent HIV. It works best when combined with other prevention methods such as: * **Using condoms** to reduce the risk of HIV and other sexually transmitted infections (STIs). * **Getting regular HIV and STI testing** to stay informed about your health. * **Encouraging HIV-positive partners to stay on treatment**, which lowers their viral load and reduces transmission risk. * **Using clean needles** if you inject drugs.\ No single method is 100% effective, but combining strategies provides the best protection.
Can I still use condoms while taking PrEP? Yes! Using **condoms along with PrEP** provides the best protection. While PrEP significantly reduces the risk of HIV, condoms also: * Prevent other sexually transmitted infections (STIs) like chlamydia, gonorrhea, and syphilis. * Offer extra protection if you miss a PrEP dose.\ If you’re comfortable using condoms, they are still a great way to protect your overall sexual health.
## Types of PrEP
Are there other daily PrEP options besides Truvada? Yes. If you are a **man who has sex with men (MSM) or a transgender woman**, there is another option: **Descovy**. A large study in MSM showed that daily use of **Descovy is just as safe and effective as Truvada** for preventing HIV.
Can Descovy be used by everyone for PrEP? No. **Descovy has not been studied in individuals assigned female sex at birth**, so it is unknown whether it provides effective protection for vaginal sex. Because of this, **Descovy should only be prescribed to MSM and transgender women** until further research confirms its effectiveness in other populations.
What are the alternatives for individuals who cannot take Descovy? For those who engage in vaginal sex or do not qualify for Descovy, **Truvada remains the preferred daily oral PrEP option**. Additionally, **cabotegravir injections (Apretude) every two months** have been shown to be highly effective for HIV prevention across all populations.
Are there different ways to take PrEP (daily vs. as needed)? Yes, there are **two main ways** to take PrEP: 1. **Daily PrEP:** One pill every day, which provides continuous protection and is recommended for all people at risk. 2. **On-Demand (Event-Based) PrEP:** This method is used by some men who have sex with men. It involves taking: * **Two pills** 2-24 hours before sex. * **One pill** every day you are having sex. * **One last pill** 48 hours after your last sexual encounter.\ This method is not recommended for women or people who inject drugs because it may not provide full protection.
Why is On-Demand (Event-Based) PrEP less effective in women and people who inject drugs? PrEP is less effective for women and people who inject drugs when not taken daily because the **drug levels in vaginal and blood tissues take longer to build up** compared to rectal tissue. * **For women**: The active drugs in PrEP (tenofovir and emtricitabine) do not reach **high enough concentrations in vaginal tissue** as quickly as they do in rectal tissue. Studies show that **daily use** is needed to maintain protection, while taking PrEP only around the time of sex (on-demand PrEP) does not provide reliable protection. * **For people who inject drugs**: Since HIV transmission occurs through the bloodstream, **consistent drug levels in the blood are needed** for protection. Daily PrEP ensures that drug levels stay high enough to block the virus if exposure occurs. For these reasons, **on-demand PrEP is not recommended for women or injection drug users**—they should take PrEP **every day** for the best protection.
## Eligibility
Who qualifies for PrEP? PrEP is for people at higher risk of HIV. You may qualify if you: * Have a sexual partner with HIV (especially if they are not on treatment). * Have multiple sexual partners or don’t always use condoms. * Are a man who has sex with men. * Are a transgender person at risk of HIV. * Inject drugs and share needles. * Have had a recent sexually transmitted infection (STI). A healthcare provider can assess your risk and determine if PrEP is right for you.
What are the risk factors that indicate someone may benefit from PrEP? You may benefit from PrEP if you: * Have **condomless anal or vaginal sex** with partners of unknown HIV status. * Have **a recent STI**, which can increase the risk of HIV. * Have **multiple sexual partners** or a partner who has multiple partners. * Have used **PEP (Post-Exposure Prophylaxis) multiple times**. * Share **needles or drug equipment** with others. * Have a **partner living with HIV** who is not consistently on treatment.\ If any of these apply to you, PrEP could be a good option.
Is PrEP recommended for heterosexual individuals? Yes! While HIV rates are lower among heterosexual people, PrEP is recommended for: * **Heterosexual individuals with an HIV-positive partner** who is not on treatment. * **People who have condomless vaginal or anal sex with multiple partners.** * **People whose partners are at higher risk of HIV** (e.g., men who have sex with men, people who inject drugs).\ Women should take **daily PrEP** rather than on-demand dosing for full protection.
Can people who inject drugs (PWID) use PrEP? Yes, PrEP is an option for people who inject drugs, but **daily use is required** for it to work effectively. PrEP is recommended for PWID who: * **Share needles, syringes, or drug equipment** with others. * Have a **partner who injects drugs and may have HIV**. * Engage in **both drug use and sex work**, which may increase risk.\ Even with PrEP, **harm reduction strategies** like using sterile needles and not sharing equipment are important.
Is PrEP appropriate for transgender individuals? Yes, PrEP is safe and effective for **transgender men and women** who are at risk of HIV. * **Transgender women** benefit from daily PrEP. * **Transgender men** who have receptive vaginal sex should also take daily PrEP.\ PrEP does not interfere with **hormone therapy**, and both can be safely used together.
Can couples where one partner has HIV use PrEP? Yes! If one partner has HIV and the other does not, PrEP can **provide extra protection**. This is sometimes called a “mixed-status” or **HIV-discordant couple**. * If the HIV-positive partner is on **effective treatment and has an undetectable viral load**, the risk of transmission is **extremely low (Undetectable = Untransmittable or U=U)**. * However, **PrEP is still an option** for added peace of mind, especially if the HIV-positive partner’s viral load is not consistently undetectable.
How do I know if I should take PrEP or just use PEP after a high-risk exposure? * **Use PEP if**: You had **a one-time high-risk exposure** (e.g., condom broke, shared a needle, or had unprotected sex with a partner of unknown HIV status). PEP must be started **within 72 hours** and taken for **28 days**. * **Use PrEP if**: You have **ongoing risk** of HIV (e.g., multiple partners, inconsistent condom use, an HIV-positive partner). PrEP is taken **before exposure** and is used for continuous protection.\ If you’ve needed PEP **more than once**, you should consider switching to PrEP.
What are the eligibility criteria for publicly funded PrEP in Canada? PrEP is publicly funded in many provinces for people at high risk of HIV. The criteria generally include: * **Men who have sex with men (MSM) or transgender individuals** with multiple partners or recent STIs. * **Heterosexual individuals** with an HIV-positive partner who is not on treatment. * **People who inject drugs** and share equipment. * **People who have had multiple courses of PEP.** * Other risk factors depending on the province you're in.
## Non-Binary and Transgender Specific Questions
Can transgender and nonbinary people on hormone therapy use daily PrEP? Yes—**there are no known drug interactions** between gender-affirming hormones and PrEP medications. Transgender and nonbinary people with HIV risk factors can take PrEP safely alongside estrogen or testosterone therapy.
Which PrEP regimens are approved for transgender women and nonbinary people assigned male at birth? * **Daily oral F/TDF (Truvada®)** * **Daily oral F/TAF (Descovy®)** * **Cabotegravir (CAB) injections every two months**
Which PrEP regimens are approved for transgender men and nonbinary people assigned female at birth who engage in receptive vaginal sex? * **Daily oral F/TDF (Truvada®)** * **CAB injections every two months** * *Note: F/TAF (Descovy®) has **not** yet been studied for vaginal exposure*
Who qualifies for on-demand (“2-1-1”) Truvada dosing? Off-label “2-1-1” dosing is restricted to **adult cisgender men who have sex with men** (MSM) who: * Request **non-daily** dosing * Have sex **infrequently** (e.g. <1× per week) * Can plan their dosing at least **2 hours before** each encounter
What are the off-label “2-1-1” dosing criteria for MSM? Off-label 2-1-1 Truvada dosing is **not FDA-approved** and **not CDC-recommended**, but may be prescribed to adult gay, bisexual, and other men who have sex with men (MSM) who meet **all** of the following: * **Request non-daily dosing** * **Have sex infrequently** (e.g., less often than once a week) * **Can anticipate or delay sex** so that doses can be taken at least **2 hours before** intercoure
## Oral Medication Eligibility Chat
IdentitySexGenderTruvada (daily)Descovy (daily)On-demand
Cisgender maleMaleMan✔✔✔
Non-binary (AMAB)MaleNon-binary, other✔✔
Transgender femaleMaleWoman✔✔
Transgender maleFemaleMan✔
Cisgender femaleFemaleWoman✔
Non-binary (AFAB)FemaleNon-binary, other✔
2-1-1 (event-driven) PrEP was evaluated **only among adult men who have sex with men** (e.g., the IPERGAY trial) and is endorsed off-label for that group. Transgender women were not enrolled in those studies, and CDC guidance does **not** recommend 2-1-1 dosing outside MSM individuals, since its safety and effectiveness have not been established in transgender individuals.
Why can't non-binary individuals assigned male at birth and transgender women use on-demand PrEP? On-demand PrEP, also known as the "2-1-1" regimen, involves taking two pills 2–24 hours before sex, followed by one pill 24 hours after the first dose, and another pill 24 hours later. This dosing strategy has been studied primarily in cisgender men who have sex with men (MSM) and is not currently recommended for transgender women or non-binary individuals assigned male at birth due to limited research on its efficacy in these populations.​ Some studies have indicated that feminizing hormone therapy in transgender women may reduce the levels of the PrEP drug tenofovir in the body, potentially affecting its efficacy. While these reductions are not large enough to affect the efficacy of daily PrEP, more research is needed before on-demand PrEP can be recommended for transgender women. ​ For non-binary individuals assigned male at birth, the lack of specific research on on-demand PrEP's effectiveness in this group means that daily PrEP is the recommended approach.
Why can't individuals assigned female at birth take Descovy for PrEP? Descovy (emtricitabine/tenofovir alafenamide) is approved for use as PrEP in individuals at risk of HIV through receptive anal sex. However, it is not approved for use in people assigned female at birth who are at risk of HIV through vaginal sex because its effectiveness has not been studied in this population. The absorption and distribution of the drug may differ in vaginal tissues compared to rectal tissues, and without specific studies confirming its efficacy in preventing HIV transmission through vaginal sex, Descovy is not recommended for this use.
## Getting PrEP
How do I get PrEP? To get PrEP, you need to: 1. **See a doctor or nurse practitioner** for an assessment. 2. **Get tested** for HIV and other conditions to ensure it’s safe to start PrEP. 3. **Get a prescription** if you qualify. 4. **Pick up PrEP at a pharmacy** (it may be covered by insurance or public health programs).
Do I need a prescription for PrEP? Yes, **PrEP requires a prescription** from a healthcare provider. You can’t buy it over the counter. A doctor or nurse practitioner will assess your risk, do necessary tests, and provide a prescription if appropriate.
Where can I go to talk to a doctor about PrEP? You can discuss PrEP with: * **Any TeleTest physician** * **Your family doctor** (if they are familiar with PrEP). * **Sexual health clinics** (these often have PrEP specialists). * **HIV clinics or infectious disease specialists**.
What tests do I need before I start taking PrEP? Before starting PrEP, you’ll need: * **An HIV test** (PrEP is only for HIV-negative individuals). * **Kidney function tests** (PrEP can affect kidney health). * **Hepatitis B and C tests** (PrEP can also treat hepatitis B, so this must be monitored). * **Sexually transmitted infection (STI) screening**. * **Pregnancy test** (if applicable).
These tests are important to ensure PrEP is safe for you and to monitor any potential health concerns.
How often do I need to see a doctor while on PrEP? After starting PrEP, you should see a doctor: * **After 1 month** for follow-up blood work. * **Every 3 months** for ongoing HIV and STI testing, kidney monitoring, and prescription renewals. * **Anytime you experience side effects or concerns**. These visits ensure that PrEP is still right for you and that you’re staying healthy.
What if I can’t afford PrEP? Are there assistance programs? Yes! If PrEP is not fully covered in your province, you can explore: * **Provincial health plans** (check if you qualify for government-funded coverage). * **Private insurance** (many plans include PrEP, so ask your provider). * **Manufacturer assistance programs** (some drug companies offer financial aid). * **Community-based HIV organizations** (they may help you access lower-cost PrEP).
How do I switch from using PEP to taking PrEP regularly? If you’ve used **PEP (Post-Exposure Prophylaxis) multiple times**, you might want to switch to PrEP for ongoing protection. The process is: 1. **Complete your full 28-day course of PEP**. 2. **Get an HIV test** to confirm you remain HIV-negative. 3. **If still at risk, start PrEP immediately after finishing PEP** (your doctor can provide a prescription in advance).\ Switching from PEP to PrEP ensures continuous protection without a gap in coverage.
## How to Take PrEP
How often do I need to take PrEP? * **Daily PrEP**: Take one pill every day for continuous protection. This is the most reliable way to prevent HIV. * **On-Demand PrEP** (for some men who have sex with men): Take pills only around the time of sex. This method is not recommended for women or people who inject drugs.\ Our doctors can help decide which method is best for you * **Injectable PrEP**: Given as a shot **every two months** for continuous protection. This is a good option for people who have trouble taking pills daily.
What happens if I miss a dose? **Truvada (daily PrEP pills)** * **If you miss a dose within 12 hours of your usual time:** Take the missed dose **with food** as soon as possible, then continue with your regular schedule. * **If you miss a dose by more than 12 hours and it’s close to your next dose:** **Skip the missed dose** and take your next scheduled dose at the usual time. * **Do not take more than one dose per day** or double up to make up for a missed dose. **Descovy (daily PrEP pills)** * **If you miss a dose within 18 hours of your usual time:** Take the missed dose **with or without food** as soon as possible, then continue with your regular schedule. * **If you miss a dose by more than 18 hours:** **Skip the missed dose** and take your next scheduled dose at the usual time. * **Do not take more than one dose per day** or double up to make up for a missed dose. If you frequently miss doses, talk to your doctor about ways to stay on track or whether a different PrEP method may work better for you.
How long does it take for PrEP to start working? How quickly PrEP protects you depends on the type and method: * **Daily PrEP (pills):** * **For anal sex** (men who have sex with men) – **7 days** for full protection. * **For vaginal sex and injection drug use** – **21 days** for full protection. * **On-Demand PrEP (pills):** * Starts working **2-24 hours** after the first two-pill dose. * Full protection requires taking the full course around your sexual activity. * **Injectable PrEP:** * Provides **protection within a few days** of the first shot. * A second shot is required after **one month**, then every **two months** for continuous protection. Until PrEP reaches full effectiveness, continue using other prevention methods like condoms.
How long does it take for daily PrEP to provide full protection? The time it takes for daily PrEP (oral pills) to become fully effective depends on the type of exposure: * **For anal sex (men who have sex with men - MSM):** PrEP reaches full effectiveness **after about 7 days** of daily use. * **For vaginal sex and injection drug use:** PrEP reaches full effectiveness **after about 21 days** of daily use. The difference is due to how the medication concentrates in different body tissues. PrEP builds up faster in rectal tissue, which is why it provides protection for anal sex within a week, whereas it takes longer to reach effective levels in vaginal and blood tissues. Until PrEP reaches full effectiveness, it is recommended to use additional prevention methods such as condoms. Reference: Centers for Disease Control and Prevention. (n.d.). *Pre-exposure prophylaxis (PrEP)*. U.S. Department of Health & Human Services. Retrieved March 7, 2025, from
How does on-demand PrEP (2-1-1) work, and when does it provide protection? On-demand PrEP (also called **2-1-1 dosing**) is an alternative to daily PrEP for men who have sex with men (MSM) engaging in receptive anal sex. This method is not recommended for vaginal sex or injection drug use. The dosing schedule is: * **Before sex:** Take **2 PrEP pills between 2 and 24 hours before sex.** * **Taking the pills closer to 24 hours before sex is better** to ensure optimal protection. * **After sex:** Take **1 pill 24 hours after the first dose**, then **1 more pill 24 hours later (48 hours after the first dose).** Protection begins as early as **2 hours after the first two-pill dose**, but levels are strongest **after 24 hours**. Full protection is only achieved if the entire **2-1-1 regimen** is completed. Skipping the post-sex doses may lower protection. Studies have shown that properly using on-demand PrEP can reduce HIV risk by about 86%.
Is on-demand PrEP effective for vaginal sex or injection drug use? No, **on-demand PrEP is not recommended** for vaginal sex or for people who inject drugs. Research has shown that PrEP drugs take longer to concentrate in vaginal and blood tissues, meaning on-demand dosing **may not provide sufficient protection** for these types of HIV exposure. For vaginal sex and injection drug use, **daily PrEP is the recommended method**, with full protection reached after about **21 days of daily use**.
How quickly does injectable PrEP (cabotegravir) start working? Injectable PrEP (**cabotegravir**, brand name **Apretude**) starts providing protection **within a few days** after the first injection. Some studies suggest that protective drug levels are reached in about **7 days**, but there is **no officially recommended “lead-in” period like the 21-day guideline for oral PrEP**. To ensure continuous protection, it is important to follow the prescribed **injection schedule**: 1. **First injection (Month 0)** – Provides initial protection. 2. **Second injection (Month 1)** – Boosts drug levels for ongoing protection. 3. **Subsequent injections every 2 months** – Required to maintain effectiveness. While cabotegravir builds up quickly, **some health authorities suggest using additional protection methods, such as condoms, until the second injection at one month**. This ensures optimal drug levels for maximum protection against HIV. Because there is no published data on the time to effectiveness and the drug was approved without specifying his 'lead in time', we recommend waiting until 7 days after the 2nd dose is administered. **Bottom line:** Although injectable PrEP works relatively fast, **patients should stay cautious during the first month and use extra precautions if needed until the second injection is received**.
Can I stop PrEP and restart later if my risk level changes? Yes! You can safely **stop PrEP if you are no longer at risk**, but you should: * Continue **PrEP for at least 28 days after your last exposure** to ensure protection. * Get an **HIV test before restarting PrEP**. * If restarting, follow the waiting period: **7 days for anal sex, 21 days for vaginal sex or injection drug use**. * Injectable PrEP may require **temporary oral PrEP if there’s a delay** in getting your next shot
## On Demand PrEP - Event Based Dosing
What is On-Demand PrEP? On-Demand PrEP, also known as **event-based dosing (EBD) or 2-1-1 PrEP**, is an alternative to daily PrEP for **men who have sex with men (MSM)** who want protection only around the time of sexual activity. Instead of taking a pill every day, On-Demand PrEP follows this schedule: 1. **Take 2 pills** of TDF/FTC (Truvada or generic equivalent) **2–24 hours before sex**. 2. **Take 1 pill per day** if you continue having sex. 3. **Take the final pill 48 hours after the last sexual encounter.** This method provides **similar (though lower) protection to daily PrEP** for MSM when taken correctly. However, **it is not recommended for everyone**.
Which PrEP Brands Are Available for On-Demand Use? Currently, **only TDF/FTC-based PrEP (Truvada or generics)** is studied and recommended for On-Demand PrEP. * **Truvada (brand name)** – Contains **tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC)**. * **Generic TDF/FTC** – Available in Canada at a lower cost. * **Descovy (TAF/FTC)** – **NOT approved for On-Demand use** because it has not been studied for this purpose.
Who is Eligible for On-Demand PrEP? On-Demand PrEP is **only recommended for men who have sex with men (MSM)** who:\ ✔ Have **infrequent** sexual activity (less than twice a week).\ ✔ Can **plan** when they will have sex (so they can take the first dose on time).\ ✔ Do **not** have hepatitis B (TDF can suppress hepatitis B, and stopping suddenly can cause flare-ups). **Who Should NOT Use On-Demand PrEP?**\ ❌ **Cisgender women and transgender individuals engaging in vaginal sex** (Drug levels take longer to build up in vaginal tissue, making On-Demand PrEP less reliable).\ ❌ **People who inject drugs** (Daily PrEP is recommended instead).\ ❌ **Anyone who has frequent or unpredictable sex** (Daily PrEP may be more suitable).
Does TeleTest Provide On-Demand PrEP Prescriptions? No, **TeleTest does not prescribe On-Demand (Event-Based) PrEP**. At this time, we only provide prescriptions for **daily PrEP**, which is the most widely recommended and studied method for HIV prevention. If you are interested in On-Demand PrEP, we recommend speaking with a healthcare provider or a specialized sexual health clinic to discuss your options.
## Stopping PrEP ### Daily Oral PrEP (TDF/FTC)
How long should I continue PrEP after my last exposure if I take daily oral PrEP for receptive anal sex? Continue daily PrEP for at least 2 days (48 hours) after your last potential HIV exposure via receptive anal sex. **Explanation:** This short “tail” period is sufficient because **drug concentrations remain high in rectal tissue for a couple of days**, maintaining protection against HIV even after stopping PrEP. [**Reference:** EACS HIV Pre-Exposure Prophylaxis Guidelines](https://eacs.sanfordguide.com/eacs-part1/art/eacs-pre-exposure-prophylaxis)
How long should I continue PrEP after my last exposure if I take daily oral PrEP for vaginal sex or injection drug use? Continue daily PrEP for at least 7 days after your last exposure via vaginal sex or injection drug use. **Explanation:** **Vaginal tissues and drug injection sites require a longer "tail period"** due to slower drug absorption. Taking PrEP for a full 7 days after the last exposure ensures sufficient protective drug levels before stopping. [**Reference:** EACS HIV Pre-Exposure Prophylaxis Guidelines](https://eacs.sanfordguide.com/eacs-part1/art/eacs-pre-exposure-prophylaxis)
### Long-Acting Injectable PrEP (Cabotegravir/Apretude)
How long does cabotegravir (Apretude) stay in my system after stopping injectable PrEP? Cabotegravir is known to provide strong protection for about 2 months after your last injection. Although the drug remains detectable in your system for up to a year, its full protective effect is only guaranteed during those first 2 months. Because we don’t yet have guidance on how long maximum protection lasts beyond that point, we recommend using an additional HIV prevention method (such as daily oral PrEP or condoms) after 2 months. Since oral PrEP also requires time to become fully effective, here are some examples of when you should begin it: * **For men who have sex with men (MSM) engaging in anal sex:** Start oral PrEP at least 7 days before your next cabotegravir injection would have been due. * **For individuals engaging in vaginal sex or using injection drugs:** Begin oral PrEP at least 21 days before your next scheduled cabotegravir injection. This approach helps ensure you have continuous protection against HIV.
What happens if I stop my injectable PrEP and skip my next scheduled injection? Long-acting injectable PrEP (Cabotegravir, Apretude) provides effective HIV prevention, but protection **gradually declines after stopping injections**. The medication remains in the body for a prolonged period, with detectable levels lasting **up to 12 months**. A detectable level by itself does not mean you are protected. However, **effective protection only lasts about 8 weeks (2 months) after the last injection**. After this period, cabotegravir levels drop below the threshold needed to reliably prevent HIV, entering a **suboptimal “tail” phase** where the drug is still present but no longer fully protective. If you **skip your next scheduled injection** and continue having sex, you could be at risk of HIV if exposed during this time.
Do I need to take oral PrEP if I stop the injection? Yes, **if you are still at risk of HIV (i.e. you plan on having sex until when your next injection is due but plan on skipping the injection), you should switch to oral PrEP to prevent a gap in protection**. Our guidelines recommend starting **daily oral PrEP (e.g., Truvada or Descovy) within 8 weeks of your last cabotegravir injection** to maintain continuous HIV prevention. * **Best practice:** Start oral PrEP **a minimum of 7 days before your next injection was due** to ensure a smooth transition. We suggest: * **For anal sex (men who have sex with men - MSM):** starting a minimum of **7 days** * **For vaginal sex and injection drug use:** starting a minimum of **21 days.** If you **do not** transition to oral PrEP, you may be at risk of HIV during the tail phase as drug levels decline.
What are the risks if I don’t take oral PrEP after stopping CAB-LA? The **biggest risk** of stopping injectable PrEP without switching to oral PrEP is **HIV infection during the “tail” period**, when cabotegravir levels are too low to provide full protection but still high enough to allow the virus to develop **drug resistance** if infection occurs. * **Risk of drug-resistant HIV:** If someone contracts HIV while cabotegravir is still in their system at low levels, the virus may develop **resistance to integrase inhibitors** (a key class of HIV medications), making treatment more complicated. * **Possible delayed HIV detection:** Low drug levels in the body may partially suppress the virus, leading to **false-negative HIV tests** or delayed diagnosis. To minimize these risks, health experts recommend **continuing PrEP (oral or injectable) or using alternative HIV prevention methods, such as condoms, after stopping CAB-LA**. Reference:
Do I need oral PrEP if I had sex right up until my next injection was due and I decide to stop injections? Yes, **if you are still sexually active and at risk of HIV, you need to transition to oral PrEP when stopping injectable PrEP**. **Oral PrEP should start within 8 weeks of your last injection, preferably a 7 days before your next shot was originally due.** If you do not take oral PrEP, you may **lose protection and increase your risk of HIV**, particularly if exposed during the tail phase. Reference:
## Injectable PrEP (Apretude)
What is Injectable PrEP? Injectable PrEP is an HIV prevention option using long-acting **cabotegravir (Apretude)**, given as a **shot every two months** instead of taking daily pills. It provides **continuous protection** against HIV for people at risk.
How is Injectable PrEP different from daily PrEP pills? * **Injectable PrEP** is given every **two months**, while daily PrEP requires a pill every day. * It is a good option for those who struggle with daily pill-taking. * Both options are **highly effective** when taken as prescribed
How often do I need to get the PrEP injection? * The first two shots are **one month apart**. * After that, injections are given **every two months** to maintain protection.
Is Injectable PrEP more effective than daily pills? Studies show that **injectable PrEP is at least as effective—if not more effective—than daily PrEP pills**, especially for people who have trouble taking pills consistently.
What tests do I need before starting Injectable PrEP? Before starting, you’ll need: * **An HIV test** to confirm you’re negative. * **Kidney and liver function tests**. * **Hepatitis B and C screening**. * **STI screening**
Can I switch from daily PrEP pills to Injectable PrEP? Yes! If you're already on PrEP pills and want to switch, a TeleTest doctor may suggest: * **Taking a lead-in period** of oral cabotegravir pills for a few weeks to check for side effects. * Or, starting with the injection directly after an HIV test.
What happens if I miss an injection? * If you **miss a scheduled injection**, get it **as soon as possible**. * If too much time has passed, your doctor may recommend taking **PrEP pills temporarily** until you can restart the injections.
## Truvada vs. Descovy for PrEP
How effective are Truvada and Descovy in preventing HIV? Both **Truvada (TDF/FTC)** and **Descovy (TAF/FTC)** are **highly effective** in preventing HIV when taken as prescribed. Studies show that **daily PrEP with either medication can reduce the risk of getting HIV from sex by about 99%** with consistent use (thought he protection rate is lower with injection drug use). * In the **DISCOVER trial**, Descovy was found to be **equally effective** (non-inferior) to Truvada for **men who have sex with men (MSM) and transgender women**. * **Adherence is key**—PrEP works best when taken **daily**, as missed doses can lower protection.
What are the side effects of Truvada and Descovy? Do they affect bone or kidney health? Both PrEP options are **well tolerated**, and most users do not experience serious side effects. **Short-term side effects:** * Some people experience **mild nausea, headache, or diarrhea** when they first start PrEP. * These symptoms, often called “startup syndrome,” usually **go away within a few weeks**. **Long-term effects:** * **Bone health**: * **Truvada (TDF/FTC)** may cause **a small decrease in bone mineral density (\~1%)**, but this loss **reverses after stopping PrEP**. In the context of age related bone mineral density losses, this 1% value is relatively small in the grand scheme of things. * **Descovy (TAF/FTC)** has **less impact on bones** and is preferred for individuals with osteoporosis or at risk of fractures. * **Kidney health**: * **Truvada (TDF/FTC)** can cause **minor kidney function changes** in some users, requiring **regular kidney function monitoring**. * **Descovy (TAF/FTC)** has **less impact on kidney function**, making it a safer choice for those with existing kidney conditions. * **Weight & cholesterol**: * **Descovy users** gained **slightly more weight (\~1-2 kg per year)** compared to Truvada users. * **Truvada slightly lowers cholesterol**, while **Descovy may slightly raise cholesterol levels**. **Bottom line:** Truvada and Descovy have **similar short-term side effects**, but Descovy is **easier on bones and kidneys**, while Truvada is **more widely available and has a longer safety record**.
Is it safe to take Truvada or Descovy if I have other health conditions like kidney disease or osteoporosis? Yes, but your doctor may recommend one over the other based on your health history: * **Kidney disease**: **Descovy is preferred** because it has **less impact on kidney function** than Truvada. * **Osteoporosis or low bone density**: **Descovy is safer** since Truvada may cause **a small decrease in bone density (though the difference in bone density loss isn't significant in our opinion)** * **Hepatitis B (HBV) infection**: Both Truvada and Descovy also **treat hepatitis B**, so if you have HBV, stopping PrEP suddenly may cause **a flare-up of the virus**—talk to your doctor first.
Can I use Truvada or Descovy as PrEP for many years? Yes! PrEP is meant for **long-term use** as long as you are at risk for HIV. * **Long-term safety studies** show **no major health concerns** for people using PrEP for years. * Your doctor will monitor your **kidney function (for Truvada users) and bone health (if needed)**. * If your risk changes, **you can stop and restart PrEP safely** with medical guidance. Most people can stay on PrEP for **as long as they need it**, with regular check-ups to ensure safety.
Do Truvada or Descovy interact with other medications? Both PrEP options have **very few drug interactions**, but be sure to inform your doctor if you take: * **HIV or hepatitis B medications** (to avoid drug resistance). * **Tuberculosis (TB) antibiotics** (rifampin may lower Descovy effectiveness). * **Certain seizure medications** (phenytoin, carbamazepine may affect drug levels). * **NSAIDs (like ibuprofen/naproxen)**—frequent use with Truvada may require extra kidney monitoring. **Most common medications, including birth control and hormone therapy, do NOT interfere with PrEP.**
How much do Truvada and Descovy cost? Is generic Truvada available? * **Truvada (TDF/FTC) is available as a generic**, making it **much cheaper** than Descovy. * **Descovy is still under patent and costs significantly more** unless covered by insurance. * **Canada**: Generic Truvada costs \~**$250/month**; Descovy costs **$1,000–$1,200/month**. Many provincial health plans and private insurance plans **cover PrEP**.
Who should take Truvada, and who should take Descovy? | Factor | Truvada (TDF/FTC) | Descovy (TAF/FTC) | | ------------------------ | ------------------------------------------------------------------- | ------------------------------------------------------------------------------------ | | Effectiveness | 99%+ protection | 99%+ protection | | Kidney safety | May slightly reduce kidney function | Safer for kidneys | | Bone health | May cause slight bone loss (\~1%) | No significant bone loss | | Weight & cholesterol | May slightly lower cholesterol | May cause slight weight gain & increase cholesterol | | Populations approved for | ll people, including MSM, women, and people who inject drugs (PWID) | Only approved for MSM and transgender women (not studied in cisgender women or PWID) | | Availability & cost | Generic available, much cheaper | Brand-only, more expensive | **Best for:** * **Truvada** – **Most people**, especially those needing a lower-cost option. * **Descovy** – Those with **kidney issues, osteoporosis, or who have insurance coverage for it**. **Important note:** **Descovy is NOT approved for cisgender women or people who inject drugs**, as it was not studied in these populations.
Medication Costs (Updated 2025) - Major Chain Pharmacies Below is a table summarizing the cost at different pharmacies. These prices are subject to change by the pharmacy and may not reflect current or up-to-date pricing, or dispensing fees from the different pharmacies. | Medication | Shoppers (SDM) | Rexall | Costco | | ------------------------ | ---------------- | ---------------- | --------------- | | Truvada (brand) | $1043/30 tablets | $1091/30 tablets | $980/30 tablets | | Truvada (generic) | $264/30 tablets | $274/30 tablets | $242/30 tablets | | Descovy (brand) - 200/10 | | | | | Descovy (brand) - 200/25 | | | | | | | | |
## Descovy and Truvada Ingredients
What does Descovy and Truvada Contain? | Type of Descovy | Active Ingredients | Use | | --------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | |

Descovy

200 mg / 25 mg

|
  1. 200 mg Emtricitabine (FTC)
  2. 25 mg Tenofovir Alafenamide (TAF)
| **Approved for PrEP** but **only for MSM & transgender women** (not approved for cisgender women or PWID). | |

Truvada

200 mg / 300 mg

|

  1. 200 mg Emtricitabine (FTC)
  2. 300 mg Tenofovir Disoproxil Fumarate (TDF)
|

Approved for PrEP for all populations, including:

|
## PrEP and Bone Health
How does PrEP affect my bone density? PrEP containing **tenofovir disoproxil fumarate (TDF/FTC)** (e.g., Truvada) has been linked to a **small drop in bone mineral density (BMD)**—about **1–2% loss** in the spine and hip during the first 6–12 months. This occurs because tenofovir can affect calcium and phosphate levels in bones. However, studies show that **this loss does not lead to an increased risk of fractures** and is considered clinically minor when weighed against PrEP’s ability to prevent HIV.
Is bone density loss from PrEP reversible? Yes! **Bone density loss from TDF/FTC PrEP is reversible** once you stop taking it. Studies show that BMD **returns to pre-PrEP levels** within **6–12 months after stopping**. Even older adults and adolescents who experienced bone loss on PrEP regained bone mass after discontinuing.
Should I take calcium or vitamin D while on PrEP? Maintaining **adequate calcium and vitamin D** is important for overall bone health, whether or not you take PrEP. While supplements are not required for all PrEP users, they **can help reduce bone loss** and improve density, especially for those with low vitamin D levels. Foods rich in calcium (dairy, leafy greens, fortified foods) and vitamin D (fatty fish, eggs, sunlight exposure) can support strong bones. **We recommend everyone supplement with 2000IU of Vitamin D daily.**
Am I at greater risk for fractures if I take PrEP? No. Large clinical trials show that **PrEP does not increase fracture risk**. A study combining data from **13 PrEP trials found no difference in fractures** between those taking PrEP and those taking a placebo. Even though a small drop in bone density occurs with TDF/FTC, **fractures are not more common** in PrEP users.
How does bone loss from PrEP compare to age-related bone loss? Bone loss from **aging is a gradual and permanent process**, while PrEP-related bone loss is **temporary and reversible**. * **PrEP-related loss**: \~1–2% decrease in BMD, which **recovers after stopping PrEP**. * **Aging-related loss**: \~0.5–2% per year starting in middle-age, which **continues without treatment** and can lead to osteoporosis. * **Postmenopausal women** and older adults naturally lose **10–20% of their bone mass over a few decades**, compared to a small temporary drop on PrEP.
Are there PrEP options that do not cause bone loss? Yes! **Tenofovir alafenamide (TAF/FTC, brand name Descovy)** is a newer PrEP option that has **little to no impact on bone density**. * In clinical trials, people taking **TAF/FTC actually gained bone density**, while those on **TDF/FTC had slight declines**. * Health agencies in **Canada** have studied the per-act risk of HIV transmission (the probability of infection from a single exposure if the source is HIV-positive and no preventive measures are used). The estimated risks are: * **Injectable PrEP (Apretude)** does not contain tenofovir and does not affect bone health. * If you have **osteoporosis or are at higher risk of bone loss**, talk to your doctor about switching to a **bone-friendly PrEP option** like **TAF/FTC or injectable PrEP**.
## HIV Transmission
What is the risk of getting HIV from a single exposure? Health agencies in **Canada** have studied the per-act risk of HIV transmission (the probability of infection from a single exposure if the source is HIV-positive and no preventive measures are used). The estimated risks are: | Exposure Route | Estimated Risk per Act (if source is HIV+) | | ----------------------------------------------------- | ------------------------------------------ | | Receptive anal intercourse (bottom) | \~1.4% (≈1 in 70 chance) | | Insertive anal intercourse (top) | \~0.11% (≈1 in 900 chance) | | Receptive vaginal intercourse (female) | \~0.08% (≈1 in 1,250 chance) | | Insertive vaginal intercourse (male) | \~0.04% (≈1 in 2,500 chance) | | Oral sex (giving or receiving) | <0.04% (very low per act) | | Sharing injection needles (IDU) | \~0.6% (≈1 in 160 chance per use) | | Needlestick injury (e.g., healthcare worker exposure) | \~0.23% (≈1 in 435 chance) | | Blood transfusion (from an HIV+ donor) | \~92.5% (≈1 in 1.1 chance) | Note: These are mid-range estimates, and actual risk may vary based on viral load, presence of STIs, and other factors. Reference data: Patel, P., Borkowf, C. B., Brooks, J. T., Lasry, A., Lansky, A., & Mermin, J. (2014). Estimating per-act HIV transmission risk: A systematic review. *AIDS*, *28*(10), 1509–1519.
Does the risk of HIV vary between different types of sex? Yes. **Receptive anal sex (bottoming)** carries the **highest sexual transmission risk (\~1.4%)** because the rectal lining is thin and absorbs the virus more easily. **Insertive anal sex (topping)** has a lower risk (\~0.11%) but is still higher than vaginal intercourse. **Vaginal sex** has lower, but still significant, risks (\~0.08% for receptive, \~0.04% for insertive).
Is HIV transmission possible from oral sex? HIV transmission through **oral sex is extremely rare**. The risk per act is estimated at **less than 0.04%**, meaning it is considered “low but not zero.” Transmission is more likely if there are **cuts, sores, bleeding gums, or an untreated STI in the mouth or genitals.**
What is the risk of getting HIV from sharing needles? **Sharing injection needles** has a **higher risk (\~0.6% per use)** because the virus enters directly into the bloodstream. Using sterile needles and harm reduction services can greatly reduce this risk.
How does HIV transmission from needlestick injuries compare? Healthcare workers who experience **needlestick injuries** from HIV-positive patients have a **\~0.23% risk (about 1 in 435 chance)** of infection per incident. Post-Exposure Prophylaxis (**PEP**) can **reduce this risk significantly** if started within 72 hours.
What factors increase or decrease the risk of HIV transmission? Several **factors can increase transmission risk**, including: * **High viral load in the HIV-positive partner** (if untreated). * **The presence of STIs**, which can cause inflammation and make transmission easier. * **Cuts, tears, or mucosal damage** in the genital or anal area. Factors that reduce transmission risk include: * **PrEP (Pre-Exposure Prophylaxis)** – reduces sexual HIV risk by **99%** if taken consistently. * **PEP (Post-Exposure Prophylaxis)** – can prevent HIV if taken within **72 hours after exposure**. * **Condom use** – significantly reduces risk for all types of sexual exposure. * **Undetectable = Untransmittable (U=U)** – People with HIV on treatment with **an undetectable viral load** cannot transmit HIV sexually.
## Symptoms of HIV
What are the symptoms of an HIV infection? Many people with acute HIV infection experience flu-like symptoms, which can include: * Fever * Fatigue (tiredness) * Swollen lymph nodes (lymph glands) * Swollen tonsils (tonsillitis) * Sore throat * Joint and muscle aches * Diarrhea * Rash
How long do the symptoms of acute HIV infection last? Symptoms **typically last around 14 days** but can vary: * Some people experience symptoms for just a few days. * Others may have symptoms for several months. * Some individuals may not experience noticeable symptoms at all
When do symptoms appear after HIV exposure? Symptoms of acute HIV infection usually begin **a few days to weeks after exposure** to the virus. This is the time when HIV is highly infectious due to high viral levels in the blood.
What should I do if I think I have acute HIV infection? If you think you may have been exposed to HIV: ✅ **Get tested for HIV as soon as possible** (consider an RNA test for early detection).\ ✅ **Avoid unprotected sex** to prevent potential transmission.\ ✅ **Talk to a healthcare or TeleTest provider** about your risk and prevention options. Early diagnosis and treatment can significantly improve long-term health outcomes.
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