PEP – Treatment after sex


PEP, or Post-Exposure Prophylaxis is a treatment that is taken soon after having unprotected anal or vaginal sex with a partner whose HIV status you don’t know.


For this treatment to be effective, it must be started as quickly as possible, within a maximum of 72 hours after the risky sexual behaviour. The sooner you seek treatment, the higher your chances of avoiding infection. Some health professionals not specializing in HIV may not be familiar with this treatment, which is why it is recommended that you consult a clinic specializing in HIV and STBBIs. If this is not possible or if you’re ever refused service, you can contact an HIV organization in your area which will be able to refer you to the right place.

PEP can be prescribed by any doctor. You can go to the hospital emergency room nearest you, or even make an appointment at a clinic or CLSC. Remember that it is important that you do this as quickly as possible and within 72 hours after the risky sexual behaviour.

If you want to know more about PEP, the following information has been provided by RÉZO.


Can you avoid an HIV infection after possibly being exposed to it?

The condom broke during your last sexual encounter? You were lost in the moment and forgot to use protection? You were engaged in activities that are high risk for an HIV infection (sharing needles, etc.)? For these situations, there exists an HIV prevention method called Post-Exposure Prophylaxis or PEP.

PEP, what is it?

PEP is the acronym for Post-Exposure Prophylaxis. In French, PPE is the acronym used for prophylaxie postexposition.

PEP is an emergency measure taken by an HIV negative person to prevent an HIV infection after a possible exposure to the virus. How? By taking antiretroviral medications for 28 consecutive days, beginning in the hours following a risky sexual encounter (up to a maximum of 72 hours). Very early administration of PEP reduces the risk of the HIV virus multiplying in the body.


Why act quickly when taking PEP?

When taking PEP, the earlier you begin the better. Studies have shown that the earlier PEP is taken after an exposure to the virus, the higher the chances are to prevent an infection. The most ideal is to begin within the hours of an exposure. After 72 hours, studies have shown that it is no longer beneficial to take antiretroviral medications to prevent an infection. During the first three days (the first 72 hours), the virus is present only in the blood, where antiretroviral medications can more easily fight it. Beyond these three days, the virus can reach and embed itself in different parts of your body. After that, it is more difficult to fight.

Under what circumstances is a PEP preventive medicine appropriate?

For HIV negative people who may have been exposed to HIV during a risky sexual encounter. An encounter with penetration is considered risky when, for example, a condom was not used for the entirety or for part of a penetration, no matter how long the duration. The use of a sex toy that was also used by your partner can also pose a risk of exposure. In certain situations, oral sex with ejaculation is also considered a risk. Those who use injection material (needles) or medical personnel can also access PEP.

Other types of HIV transmission also exist: by human bites or by being exposed to blood or genital secretions on a mucus membrane (eye, nose) or on skin where there is an unhealed wound or scrape (entry point into the body). It is also possible to be pricked accidentally by the needle of an unknown person found lying around.

PEP can be prescribed for when a condom has broken during anal or vaginal sex or when a man has unprotected anal sex with an HIV positive partner or with a partner whose status they aren’t aware of. Medical professionals will evaluate the possible risks of infection of HIV and the pertinence of prescribing PEP.

What happens during an evaluation for PEP?

During your first visit, a medical professional will evaluate with you the necessity of administering PEP. For that, they will determine:

  • Your current HIV status by offering you a rapid HIV test. If the result is positive, PEP will not be prescribed;
  • When possible, the HIV status of the person with whom you had the sexual encounter (which must be either HIV positive or unknown);
  • If the person is HIV positive, it’s possible that the following will also checked: their viral load, any viral resistances that they may have, and the antiretroviral medication that they are currently taking. PPE is not recommended when the viral load is undetectable;
  • The amount of time since the risky sexual encounter (keep in mind, the evaluation must happen within 72 hours of the exposure – ideally within 2 hours. Any later than that, PEP will not be prescribed);
  • The level of possible risk: situations that lead to a high risk of exposure are often unprotected anal or vaginal penetration or by the sharing of injection materials.

Where can I access PEP?

To access PEP in Quebec, go directly to a hospital emergency room or a specialized clinic able to offer PEP. If you experience difficulties, get in touch with an HIV organization in your area.

info3To find  an organization near you, enter your postal code in the search tool located in the right hand column.
If you live in Montreal, don’t hesitate to call one of RÉZO’s outreach workers at 514-521-7778, ext 226

Specialized clinics in Montreal:

Medical Clinic Quartier Latin

905, René-Lévesque Blvd East, Montreal

514 285 5500

* if you don’t have a family doctor, the appointment is with an STBBI screening nurse.

Medical Clinic L’Actuel

1001, de Maisonneuve Blvd East, # 1130, Montreal

514 524 1001

Medical Clinic OPUS

1470 Peel, Tower A, 8th floor, Suite 850, Montréal

514 787 6787

SIDEP+ Clinic

By appointment only

1705, de la Visitation, Montreal

514-527-2361, ext. 1661

Book an appointment online using their secure system


PEP is offered in hospital emergency rooms, including :

Saint-Luc Hospital (EMERGENCY)

Address: 1058, rue Saint-Denis, Montreal

Telephone: 514-890-8000


A PEP prevention medicine consists of what and how does it work?

A PEP preventive medicine consists of regularly taking antiretroviral medications for 28 days (4 weeks) and a medical follow-up.

The preventive medicine is a combination therapy (2 pills where one is a combination of two medications and the other consists of only one medication). These comprise of antiretroviral medications designed to fight the multiplication of the virus in the blood system. The antiretrovirals administered in the context of PEP are generally the same which are used in the treatment taken by an HIV positive person.

Starting quickly and taking the medicine in a strict manner, every day and by following the schedule prescribed by the doctor, the medications will stay highly concentrated in the blood system during the 28 days of the medicine, therefore effectively fighting the virus to avoid an infection. It is important to know that a PEP preventive medicine offers a solution, but is not without certain side effects on the body that can be hard to endure during the 28 day medicine. Read more about this below under the section “What are the side effects of PEP?”.

A take-home kit may be given by the medical staff. It contains medication for 3 days and a prescription for 4 days of medicine, which will be prolonged after a second appointment with the physician. Not all establishments will necessarily give a take-home kit and may prescribe directly 28 days. The first pills are to be taken (with or without food) as early as possible.

The follow-up for a PEP is generally done over 6 appointments. As mentioned above, the first appointment consists of an evaluation for the pertinence of prescribing PEP. You will return to see the physician for a second and third appointment, 2 and 4 weeks after the first visit, to follow-up on any possible side-effects that you may experience after beginning your medication. At each appointment, the medication may be adjusted, continued or stopped, depending on how your body responds to the medicine. The other appointments consist of an HIV test, done by a blood sample, taken 3 months after the possible exposure to HIV and possibly other STBBI’s tests.

How effective is PEP?

As much as PEP reduces the chance of contracting HIV, this preventive medicine is not absolute. We know that the earlier the medication is started and the more strictly a person follows their medicine, the better the chances of success. So, if during the 28 days you follow the instructions correctly for your preventive antiretroviral medicine, the medication will stay adequately concentrated in the blood to fight the virus. Therefore, it is important to take the medications daily and on a strict basis to ensure the effectiveness of the medicine.

Given that PEP is not 100% guaranteed to be effective, it is recommanded that those following a PEP preventive medicine use condoms during all sexual encounters during the 3 months following the possible exposure to HIV.

What will happen if I don’t properly follow the medicine?

In a situation where you may forget or don’t respect the prescribed dosage, the concentration of antiretrovirals in the blood risk being at an insufficient amount to stop the infection of HIV, allowing the virus to multiply and infect the person. Therefore it is essential to not miss any doses and to take the medicine for the entire period of time that it is prescribed.

What are the side-effects of PEP?

Once a physician prescribes PEP, they will explain the possible side effects you may experience. Most of these side-effects are temporary and will go away on their own, but some must be evaluated by a physician. It is important to discuss side effects with a health professional.

These side-effects may occur when taking PEP: fatigue, vomiting, diarrhea, head-aches, dizziness, loss of appetite. There exist some solutions to ease these effects. You can discuss these with the medical professionals, if needed.

The side-effects will stop once the medication is finished.

How much does PEP cost?

The price of a PEP medicine (28 days) is around $1 500 to $2000. The price varies depending on the type of medicine.

The medicine is covered by the Régie d’assurance medicaments du Québec (RAMQ), which makes the maximum contribution by people covered around 85$.

Those covered by private insurance must enquire with their insurance company to know the amount that may be covered, which can vary from company to company. Some may require that you pay the full amount before being reimbursed.

Would you like to speak about a certain situation and PEP with a counsellor?

Remember that if you think you may need PEP, it is important to not waste time and to act quickly by going to a clinic or a hospital emergency room, as mentioned above.

Staying informed is giving yourself the chance to make the best decisions for you. Below you will find different internet resources that were consulted as well as complimentary information. If you want to talk with an intervention worker, get in touch with an HIV organization in your area.

info3To find  an organization near you, enter your postal code in the search tool located in the right hand column.
If you live in Montreal, don’t hesitate to call one of RÉZO’s outreach workers at 514-521-7778, ext 226


Source material consulted for this article and complimentary information

What is the difference between PEP and PrEP?

As explained previously, PEP is taking a medication after being exposed to HIV. Pre-Exposure Prophylaxis (PrEP) is then another HIV prevention method. PrEP is taking a preventive medicine before a potential exposition to HIV (anal sex, etc.) to reduce the risk of infection. Click here to learn more about PrEP.