- What is PEP?
- What is the difference between PEP and PrEP?
- Is PEP right for me?
- Is PEP safe?
- How can I get PEP?
- What will happen before and after I take PEP?
- How well does PEP work to prevent HIV transmission?
- What are some other ways to help prevent HIV and other infections?
What is PEP?
Post-exposure prophylaxis, or PEP, can be used by people who are HIV negative to help prevent getting HIV after a potential exposure to HIV. PEP is a combination of three HIV medications that an HIV-negative person takes orally for 28 days to lower their chance of getting HIV.
PEP needs to be started as soon as possible (up to a maximum of 72 hours) after a potential exposure to HIV. The sooner PEP is started, the more likely it is to work. If you think you may have been exposed to HIV, don’t delay. Contact a healthcare provider immediately.
PEP is meant to be used to prevent HIV transmission from a single accidental exposure to HIV. PEP should not be used regularly as an HIV prevention strategy. If a person is at ongoing risk for HIV, they may be a good candidate for HIV PrEP (pre-exposure prophylaxis).
What is the difference between PEP and PrEP?
PEP is meant to be used to prevent HIV transmission from a single accidental exposure to HIV. PEP should not be used regularly as an HIV prevention strategy. If a person is at ongoing risk for HIV, they may be a good candidate for HIV PrEP (pre-exposure prophylaxis).What is the difference between PEP and PrEP?
PEP is not the same as PrEP, which involves taking two HIV medication on an ongoing basis.
| Differences between PEP and PrEP | |
| PEP | PrEP |
| Taken as soon as possible after a potential exposure to HIV (up to a maximum of 72 hours) | Taken before and after potential exposure to HIV |
| Taken every day for 28 days | Taken on an ongoing basis |
| Intended to be used to prevent HIV transmission from a single accidental exposure | Intended for regular use as an ongoing HIV prevention method |
Is PEP right for me?
If you have had a potential exposure to HIV within the last 72 hours, then PEP might be right for you. The sooner you start PEP, the more effective it is.
PEP can be used after a potential exposure to HIV through sex or injection drug use. This can include having sex without using any HIV prevention method (such as a condom or PrEP), having a condom break during sex or sharing equipment used to inject drugs. It can also include experiencing a sexual assault.
PEP can also be used after a potential exposure to HIV at work, such as when a healthcare worker or emergency responder has an accidental needle-stick injury.
A healthcare provider will help you determine if you should start PEP, based on the nature of your exposure. It’s important to be honest about your potential exposure so the healthcare provider can properly assess your risk. PEP is usually only recommended if the potential exposure carries a high or moderate chance of passing HIV.
PEP can be used by people of all genders, including trans and nonbinary people. Tell your healthcare provider if you are taking gender-affirming hormones so they can make sure to prescribe a drug combination that will not interfere with your hormones.
PEP can be taken by pregnant people safely. Tell your healthcare provider if you are pregnant or planning to have a baby so they can prescribe a drug combination that is safe for you. Breastfeeding (also called chestfeeding) is not recommended while taking PEP.
Is PEP safe?
Some people who take PEP experience temporary side effects such as nausea, fatigue and diarrhea. For most people, side effects are mild and manageable. Side effects can vary depending on the type of drugs prescribed for PEP and the person who is taking them. Talk to a healthcare provider if you are having side effects from PEP.
How can I get PEP?
PEP needs to be prescribed by a healthcare provider. If you think you have been exposed to HIV, you should immediately contact a healthcare provider such as your family doctor or nurse practitioner, or you can go to a hospital emergency room or sexual health clinic. In some regions, pharmacists are also able to prescribe PEP. A healthcare provider will ask you questions to determine if you need PEP. Sometimes a “starter pack” (a partial supply) of PEP is provided to help you start PEP right away, along with a prescription for the rest of the medication.
It may also be possible to get a prescription for PEP in advance, before an exposure occurs. This is called “PEP in pocket”, or PIP. It allows you to start taking PEP right away if you think you’ve been exposed to HIV. If you are interested in PIP you will need to talk to a healthcare provider. It’s relatively new so some healthcare providers may not know about it. After starting PIP, you need to see a healthcare provider as soon as possible for testing and follow-up.
PIP can be a good option for people who have very infrequent or unexpected HIV exposures. However, if you think you might have ongoing or more frequent exposures to HIV, you should consider PrEP. For many people who are at ongoing risk for HIV, PrEP is a better choice than PIP.
The HIV medications used in PEP are often expensive, and coverage for the cost varies across Canada. If your potential exposure happened while you were working, PEP is usually covered. PEP is covered by some public and private health insurance plans after a potential exposure through sexual and drug use activities. However, this varies by province or territory and can also vary depending on the type of exposure (e.g., sexual assault versus consensual sex). PEP is often covered if it is necessary after a sexual assault.
You may want to ask your doctor or nurse practitioner, a pharmacist, a sexual health clinic or an HIV organization about ways to help cover the cost of PEP.
What will happen before and after I take PEP?
Before starting PEP you will be tested for HIV. If you test positive for HIV after starting PEP, a healthcare provider can help you safely stop PEP and start HIV treatment.
Before starting PEP you will have your kidney (and possibly liver) function tested, and you will also likely be tested for other sexually transmitted infections (STIs) and blood-borne infections, depending on the nature of your exposure. This is because the same activities that pass HIV can also pass other infections.
People on PEP need to take PEP medications every day for 28 days. Talk to your healthcare provider if you think you will have trouble remembering to take your pills every day. They may be able to help you come up with a strategy that will work for you.
After completing the 28 days of PEP, you will need to be tested for HIV to assess whether PEP has worked. Retesting is recommended four to six weeks after your potential exposure to HIV, and again 12 weeks after the potential exposure.
If you have an ongoing chance of getting HIV, PrEP could be a good prevention option for you. Talk to a healthcare provider about whether PrEP is right for you.
How well does PEP work to prevent HIV transmission?
PEP does not prevent 100% of HIV infections but it is very effective at preventing HIV if used every day for 28 days. PEP should ideally be started right away, but it can be started up to a maximum of 72 hours after a potential exposure to HIV. The sooner you start PEP, the more effective it is.
To maximize the effectiveness of PEP:
- Get PEP prescribed by a healthcare provider
- Start taking PEP as soon as possible after an exposure (up to 72 hours after)
- Take PEP medications as prescribed, typically every day for 28 days
- Use other prevention strategies (e.g., condoms or new needles) to avoid other potential exposures while taking PEP
What are some other ways to help prevent HIV and other infections?
PEP is the only way to help prevent HIV after a potential exposure to HIV. It is for emergency use only. It is not meant to be used as a long-term HIV prevention strategy.
There are several ways to help prevent HIV before you are exposed to HIV:
PrEP
PrEP is a highly effective way to prevent getting HIV when used as prescribed, on an ongoing basis, starting before and continuing after exposure to HIV.
Condoms
Condoms are highly effective at preventing both HIV and other sexually transmitted infections if used consistently and correctly.
New drug use equipment
For people who inject drugs, using new injection equipment each time is a highly effective strategy to prevent HIV, hepatitis B and C, and other infections.
Maintaining an undetectable viral load
When people with HIV take treatment and maintain an undetectable viral load, they do not pass HIV on to their sex partners. Their risk of passing HIV through sharing needles is also reduced, but we don’t know exactly how much. If you have a partner with HIV who is on treatment and maintaining an undetectable viral load, this is a highly effective strategy to prevent the sexual transmission of HIV.
Universal precautions
In a work context, it is important to use universal precautions, such as wearing gloves, disinfecting surfaces and handling and discarding sharps safely, to avoid coming into contact with bodily fluids that may pass HIV or other infections.