What is PEP? Emergency HIV prevention after exposure

If you think you may have been exposed to HIV, you need to know that there is a time-sensitive medication that can prevent the virus from establishing an infection in your body. It is called PEP, and it could be one of the most important medical interventions you ever learn about. This guide will walk you through everything you need to know about PEP in the Philippines, including what it is, when to start it, where to find it, how much it costs, and what to expect while taking it.

What does PEP stand for?

PEP stands for Post-Exposure Prophylaxis. Let us break that down:

• Post-exposure means you take it after a potential exposure to HIV has already occurred.
• Prophylaxis means a treatment used to prevent a disease, not to cure it.

In plain terms, PEP is an emergency course of antiretroviral (ARV) medication taken by someone who does not have HIV but who may have been recently exposed to the virus. Think of it like an emergency brake for HIV. It is not a morning-after pill, a vaccine, or a cure. It is a medically proven intervention that, when started quickly and taken correctly for the full 28 days, can stop HIV from taking hold in your body.

The Philippine Department of Health (DOH) and the World Health Organization (WHO) both recommend PEP as a critical tool in HIV prevention. In the Philippines, where new HIV cases continue to rise, understanding PEP could make a real difference for you or someone you know.

The 72-hour window

The single most important fact about PEP is that time is critical. PEP must be started within 72 hours (three days) of a potential exposure to HIV. After 72 hours, PEP is no longer considered effective, and healthcare providers will generally not prescribe it for that exposure event.

However, 72 hours is the absolute maximum. Medical guidelines stress that PEP is significantly more effective the sooner it is started. Ideally, you should begin PEP within the first 24 hours after exposure. Animal studies suggest that starting as soon as possible after exposure provides the strongest protection.

Why sooner is better

When HIV enters your body, it does not immediately establish a permanent infection. The virus needs time to attach to cells, replicate, and spread. During this brief window, the antiretroviral drugs in PEP can block the virus from completing that process.

The longer you wait, the more time the virus has to replicate and integrate into your cells. Once HIV has established itself in your body's immune cells, PEP can no longer prevent infection. That is why urgency matters so much.

If you think you have been exposed, do not wait until morning. Do not wait until Monday. Go to the nearest hospital emergency room or DOH treatment hub right away.

Who should consider PEP?

PEP is recommended for anyone who is HIV-negative (or does not know their status) and has had a recent exposure that carries a meaningful risk of HIV transmission. The main categories include:

Sexual exposure

• Unprotected anal or vaginal sex with a partner whose HIV status is unknown or who is known to be living with HIV
• A condom breaking or slipping during intercourse with a partner who may have HIV
• Sexual contact where there was potential exchange of body fluids — including blood, semen, rectal fluids, or vaginal fluids

Occupational exposure

• Healthcare workers who experience a needlestick injury or are exposed to blood or body fluids from a patient who may have HIV
• Laboratory workers who handle specimens containing HIV
• First responders exposed to blood at the scene of an accident

Sexual assault

• Survivors of sexual assault or rape should be offered PEP as part of their post-assault medical care, regardless of the perpetrator's known HIV status
• In the Philippines, PEP should be made available to sexual assault survivors at hospitals equipped to provide post-assault care
• No one should be turned away or judged when seeking PEP after an assault

If you are unsure whether your situation warrants PEP, err on the side of caution and consult a healthcare provider as soon as possible. It is always better to ask and be told you do not need it than to miss the window.

How PEP works

PEP uses the same class of medications used to treat HIV: antiretroviral drugs (ARVs). The standard PEP regimen recommended by the WHO consists of a combination of two or three ARV medications taken together for 28 consecutive days.

The most commonly prescribed PEP regimen in the Philippines typically includes:

• Tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) or emtricitabine (FTC) as the backbone
• Plus a third drug such as dolutegravir (DTG), which is the preferred integrase inhibitor

These drugs work by blocking HIV at different stages of its replication cycle. By preventing the virus from copying itself and spreading to new cells, the medications give your immune system the chance to clear the virus before it can establish a permanent infection.

What to expect during the 28 days

Completing the full 28-day course is essential. Stopping early, even if you feel fine, reduces the effectiveness of the treatment. During the course, you will:

• Take your prescribed medication every day at approximately the same time
• Attend a follow-up visit with your healthcare provider, usually around day 14
• Report any side effects or concerns to your provider
• Avoid potential re-exposure to HIV during the treatment period
• Practice safer sex (use condoms) while on PEP

Your healthcare provider will also test you for HIV at the start of PEP to confirm you are HIV-negative before beginning the regimen. If you are already HIV-positive, PEP is not the appropriate treatment. You would instead be transitioned to full ARV therapy.

Where to get PEP in the Philippines

Finding PEP quickly is crucial given the 72-hour window. Here are the main places where you can access PEP in the Philippines:

DOH treatment hubs

The Department of Health operates a network of HIV treatment hubs across the country. These facilities are specifically equipped to provide HIV-related services, including PEP. Treatment hubs are located in major hospitals in Metro Manila and key cities across Luzon, Visayas, and Mindanao. PEP at DOH treatment hubs is typically provided free of charge.

You can find your nearest treatment hub through the Vitamigo directory.

Hospitals and emergency rooms

Many large hospitals, particularly those in urban areas, can provide PEP through their emergency departments or infectious disease units. If you arrive at an ER after a potential exposure, inform the attending physician that you need PEP. Not all ERs stock PEP medications, but they can refer you to a facility that does.

Major hospitals in Metro Manila that commonly provide PEP include:

• San Lazaro Hospital (Manila)
• Research Institute for Tropical Medicine (RITM, Muntinlupa)
• Philippine General Hospital (Manila)
• Jose Reyes Memorial Medical Center (Manila)

Private clinics

Some private infectious disease clinics and sexual health clinics also prescribe PEP. Private clinics may be a faster option if DOH hubs are far from your location, but the cost will be higher since you will need to pay for the medications yourself.

How much does PEP cost?

The cost of PEP in the Philippines varies depending on where you access it:

• Free at DOH treatment hubs — The Department of Health provides PEP at no cost through its network of accredited treatment hubs. This includes the medication, baseline laboratory tests, and follow-up visits.
• PHP 3,000 to PHP 15,000 at private facilities — If you obtain PEP through a private clinic or hospital, you will need to pay for the ARV medications and any associated consultations and lab tests. The price varies depending on the specific drugs prescribed and the facility.

Cost should never be a barrier to accessing PEP. If you cannot afford private treatment, go to the nearest DOH treatment hub. Under Republic Act No. 11166 (the Philippine HIV and AIDS Policy Act), HIV prevention services, including PEP, should be accessible to all Filipinos.

Side effects of PEP

Like most medications, PEP can cause side effects. The good news is that most side effects are mild and temporary, typically resolving within the first one to two weeks of treatment. Common side effects include:

• Nausea — the most frequently reported side effect, especially in the first few days
• Fatigue and tiredness — you may feel more drained than usual
• Headache — mild to moderate headaches are common
• Diarrhea — loose stools may occur, particularly early in the course
• Dizziness — some people experience mild lightheadedness
• Difficulty sleeping — occasional sleep disturbances have been reported

These side effects are manageable and should not prevent you from completing the full 28-day course. Taking your medication with food can help reduce nausea. If side effects become severe or persistent, contact your healthcare provider. They may be able to adjust your regimen or prescribe supportive medications.

Serious side effects are rare but can include changes in kidney function or liver enzyme levels. Your provider will monitor these through blood tests during follow-up visits.

PEP vs. PrEP

People sometimes confuse PEP and PrEP because the names sound similar, but they serve very different purposes. Here is a clear comparison:

If you find yourself needing PEP more than once, it may be worth discussing PrEP with your healthcare provider. PrEP is a daily medication that provides continuous protection against HIV and may be a better fit for your situation. You can learn more in our complete PrEP guide for Filipinos.

What happens after completing PEP?

Finishing the 28-day course of PEP is a significant accomplishment, but it is not the final step. Follow-up care is essential to confirm that PEP was successful and that you remain HIV-negative.

Follow-up HIV testing schedule

After completing PEP, you will need to take follow-up HIV tests to confirm your status:

• At 1 month after completing PEP — An initial follow-up test to check for early seroconversion. Some newer fourth-generation tests can detect HIV at this stage.
• At 3 months after completing PEP — A confirmatory test at the three-month mark. Most guidelines consider this the definitive test for determining whether PEP was successful.

Until you receive a confirmed negative result at the three-month test, you should continue to practice safer sex and take precautions to avoid potential exposure.

Your healthcare provider may also check your kidney and liver function during follow-up visits to ensure the medications did not cause any lasting effects.

What to do after potential exposure

If you believe you have been exposed to HIV, here is a step-by-step guide to follow:

Do not shower or clean the area of exposure before seeking care, as medical staff may need to assess the situation. If the exposure was through sexual assault, seek help at a hospital with a women's or child protection unit where trained staff can provide comprehensive post-assault care.

Frequently asked questions

Is PEP the same as PrEP? No. PEP is taken after a potential exposure to HIV and lasts 28 days. PrEP is taken before exposure on an ongoing basis. Both use antiretroviral medications, but they serve different purposes. You can read more about PrEP in our PrEP guide.

Can I get PEP over the counter in the Philippines? No. PEP requires a prescription from a licensed physician. You will need to visit a DOH treatment hub, hospital, or private clinic to be assessed and prescribed PEP.

Does PEP have a 100% success rate? No medication is 100% effective. However, when started early (within 24 hours) and taken correctly for the full 28 days, PEP is highly effective at preventing HIV infection. Its effectiveness decreases the longer you wait to start.

Will taking PEP make me test positive for HIV? No. PEP medications are antiretroviral drugs, not the virus itself. Taking PEP will not cause a false positive HIV test result.

Can I drink alcohol while on PEP? It is generally recommended to avoid excessive alcohol consumption while on PEP, as alcohol can interfere with your ability to take the medication consistently and may worsen side effects like nausea. Occasional moderate drinking is unlikely to affect the medication's effectiveness, but discuss this with your doctor.

What if I miss a dose of PEP? If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose to make up for a missed one. If you miss multiple doses, contact your healthcare provider.

Can I get PEP if I do not know whether the other person has HIV? Yes. PEP decisions are based on the level of risk of the exposure, not on confirmed knowledge of the other person's status. If the exposure carries a meaningful risk, PEP may be recommended.

Is PEP safe for pregnant or breastfeeding women? PEP can be prescribed during pregnancy and breastfeeding. The benefits of preventing HIV infection generally outweigh the risks. Your healthcare provider will select the safest regimen for your situation.

How many times can I take PEP? There is no strict limit, but repeated use of PEP suggests that PrEP may be a more appropriate long-term prevention strategy. Talk to your healthcare provider about transitioning to PrEP if you find yourself needing PEP more than once.

Take the next step

If you have had a potential exposure to HIV, do not wait. Time is your most valuable resource when it comes to PEP. Visit the nearest DOH treatment hub or hospital emergency room as soon as possible.

Use the Vitamigo facility directory to find the closest HIV service provider in your area. You can also read our guide on how to get tested for HIV in the Philippines to learn about the testing process.

Remember: seeking PEP is a responsible and courageous decision. No matter how the exposure happened, you deserve access to care without judgment. Healthcare providers at DOH treatment hubs are trained to help you with compassion and confidentiality.

Sources and references

1. World Health Organization. Guidelines on post-exposure prophylaxis for HIV and the use of co-trimoxazole prophylaxis for HIV-related infections among adults, adolescents and children. who.int
2. Centers for Disease Control and Prevention (CDC). About HIV. cdc.gov
3. HIV.gov. What Are HIV and AIDS? hiv.gov
4. Centers for Disease Control and Prevention (CDC). Updated Guidelines for Antiretroviral Postexposure Prophylaxis After Sexual, Injection Drug Use, or Other Nonoccupational Exposure to HIV.
5. Department of Health, Philippines. Philippine HIV and AIDS Policy Act (Republic Act No. 11166). doh.gov.ph
6. Epidemiology Bureau, Department of Health, Philippines. HIV/AIDS and ART Registry of the Philippines (HARP). doh.gov.ph
7. UNAIDS. Country factsheet: Philippines.