What is Post-Exposure Prophylaxis (PEP)?

Disclaimer: The information provided in this article is for informational and educational purposes only. Please consult with your doctor for any medical advice or concerns.

HIV, or Human Immunodeficiency Virus, is a serious infection that can lead to AIDS (Acquired Immunodeficiency Syndrome). While prevention is crucial, sometimes accidents or unforeseen circumstances can lead to potential exposure to HIV. In such cases, Post-Exposure Prophylaxis (PEP) becomes a crucial option for reducing the risk of HIV infection. This article delves into what PEP is, its purpose, usage, effectiveness, and more.

What is PEP?

PEP, short for Post-Exposure Prophylaxis, is a preventive treatment aimed at reducing the risk of HIV infection following potential exposure. It involves taking a 28-day course of antiretroviral medication after a specific event that may have put an individual at risk of HIV transmission.

When is PEP Used?

PEP is recommended in situations involving high-risk exposure to HIV, such as:

Timing Matters: Starting PEP

PEP is most effective when initiated within 72 hours of potential exposure, though it may still be considered up to 72 hours after the exposure event. The sooner PEP is started, the better the chances of preventing HIV infection.

How to Start PEP?

If you believe you’ve been exposed to HIV, it’s crucial to act swiftly. Here’s what to do:

Visit a healthcare facility or clinic experienced in PEP treatment, like clinics specialising in sexual health.

Your healthcare provider will conduct an HIV test to determine your current HIV status. Although this will not be conclusive for the immediate risky exposure it does tell us if there is any pre-existing HIV in your system that you may be unaware of thus rendering PEP ineffective.

If you are at high risk of HIV transmission and test negative, you’ll be prescribed a 28-day course of PEP medication. It’s essential to follow the treatment plan diligently.

During PEP treatment, you will have regular follow-up appointments to monitor your health and ensure adherence to the medication.

Effectiveness of PEP

PEP can significantly reduce the risk of HIV transmission when taken correctly and as prescribed. However, it is not 100% effective. The efficacy of PEP depends on various factors, including the timing of initiation and adherence to the treatment regimen.

Side Effects

PEP may cause side effects, similar to those experienced with some HIV medications. These can include nausea, fatigue, and diarrhoea. It’s essential to discuss potential side effects with your healthcare provider and report any unusual or severe symptoms promptly so countermeasures may be taken.

PEP is Not Recommended for All Situations

While PEP is a valuable tool in reducing the risk of HIV transmission, it is not a substitute for consistent HIV prevention methods, such as safe sex practices and pre-exposure prophylaxis (PrEP) for those at high risk. PEP is designed for specific post-exposure situations.


PEP is an essential option for individuals who have experienced high-risk exposure to HIV. It is a time-sensitive intervention that, when taken correctly, can significantly reduce the risk of HIV infection. If you believe you’ve been exposed to HIV, seek immediate medical attention, get an HIV test, and discuss the potential use of PEP with a healthcare professional. Remember that the best defence against HIV is prevention, so practising safe sex and adhering to HIV prevention methods remains paramount.

Disclaimer: We have attempted to provide full, accurate and up to date information in this blog, based on current medical evidence and opinion. However, information and advice may vary from different sources, and over time. If you have any further questions, see your doctor for a more accurate diagnosis of your concerns.

Make a call or fill form

Come and speak to our friendly and approachable doctors

Feel free to come and speak to our friendly and approachable doctors about any issues you may be having. Remember we still cover all the GP stuff as well. 

Our Promise

Why choose us

Tailored Approach

Tailored Approach

Here at Atlas Pacific Medical, our doctors are committed to providing quality healthcare tailored to each individual's unique needs.

Experienced Doctors

Our team of experienced physicians provide confidential testing and treatment services to ensure you are able to receive the care you need.
Compassionate Service

Compassionate Service

Our mission is to provide the most supportive care possible, while helping you make informed decisions about your sexual health.
Frequently Asked Questions


When should I go for STD screening?

You should consider screening if you have symptoms of a possible STD, if you have had a recent risky exposure (unprotected sex with a casual partner), or both.

Can I get STDs from oral sex?

Yes, you can. The common misconception is that oral sex is not considered ‘real’ sex and therfore has no risk but the opposite is true. Often oral sex is performed without protection and this is why infections such as chlamydia and gonorrhoea can pass on through oral sex.

Can STDs be cured?

Thankfully the majority can be cured but there are some such as Herpes and HIV that can be treated but not cured. This is why prevention is better than cure and ensuring safe sex goes a long way to reduce your risks.

Senior man with young female doctor in the yard