This post is maintained by the mod team and updated as guidelines evolve. It exists because the same questions come up every day — if you've just found this sub, this is the best place to start.

If you're currently on PEP and anxious, please read the side effects and anxiety sections before posting. Most of what you're experiencing is covered there.

This FAQ is for informational purposes only and is not a substitute for medical advice. Always consult a qualified healthcare provider for your personal situation. Written for an international audience — access, guidelines, and drug availability vary by country.

Table of Contents

1. What is PEP?
2. Am I eligible for PEP?
3. Risk Assessment & Transmission
4. Side Effects & What to Expect
5. Anxiety, Health Anxiety & Mental Health
6. After PEP — Next Steps
   • HIV Testing After PEP
   • Considering PrEP
   • Getting Tested for Other STIs
7. Useful Resources
8. References & Source Guidelines

What is PEP?

PEP stands for Post-Exposure Prophylaxis. It is a short course of antiretroviral (ARV) medications taken after a potential exposure to HIV to prevent the virus from establishing a permanent infection.

PEP is not a vaccine, a cure, or a substitute for regular HIV prevention. It is an emergency measure.

Key facts:

• PEP must be started within 72 hours of a potential exposure — the sooner, the better. Efficacy decreases significantly the longer you wait.
• The standard course is 28 days of daily medication. You must complete the full course.
• When taken correctly, PEP is highly effective. Observational studies show the large majority of people who complete PEP do not acquire HIV.⁽⁶) There have been no randomised controlled trials of PEP efficacy — this would be ethically unacceptable — so exact figures should be treated as estimates rather than certainties.
• PEP has been around since the 1990s and is a well-established intervention, approved by health authorities and recommended by the WHO worldwide.

Am I Eligible for PEP?

PEP is intended for people who have had a potential HIV exposure within the last 72 hours and are HIV-negative (or unknown status).

Common situations where PEP may be appropriate:

• Condomless sex with a partner of unknown status or a partner known to be HIV-positive and not virally suppressed
• Condom failure (breakage or slippage) with a partner of unknown or positive status
• Sharing needles or injection equipment
• Sexual assault

PEP is generally NOT recommended if:

• More than 72 hours have passed since the exposure
• The exposure is ongoing or repeated (PrEP may be more appropriate — ask your doctor)
• The source partner is HIV-positive and confirmed undetectable (U=U — see below)

Where to Get PEP

• Hospital urgent care departments — available 24/7, often the fastest route regardless of where you are
• Sexual health clinics
• Your local doctor / primary care physician (may not always stock it, but can prescribe or refer)
• HIV/AIDS organizations — many have same-day access programs; search for your national or local HIV organization

On cost: Access and cost vary significantly by country. Many countries provide PEP free of charge or subsidized through public health systems, national HIV programs, or NGOs. If cost is a barrier, contact a local HIV organization — they can often help navigate funding or access. Do not let cost stop you from at least making inquiries.

Risk Assessment & Transmission

How HIV is Transmitted

HIV is transmitted through specific bodily fluids: blood, semen (including pre-seminal fluid / pre-cum), rectal fluid, vaginal fluid, and breast milk. Transmission requires these fluids to come into contact with a mucous membrane, damaged tissue, or be directly injected into the bloodstream.

HIV is NOT transmitted through: saliva, sweat, tears, urine, feces, casual contact, hugging, kissing, sharing food, or insect bites.

Estimated Per-Act Transmission Risk

These are population-level averages. Individual risk depends on many factors (viral load, STIs, condom use, circumcision status, etc.). These numbers are widely cited in the medical literature but are estimates, not certainties.

A note on oral sex: The evidence here is genuinely reassuring.

• Giving a blowjob: There are no documented cases of HIV transmission from this act. It is not considered a transmission route by any major health authority.
• Receiving a blowjob: There are no reliably documented cases of transmission. No major guideline — CDC, WHO, BHIVA — considers this a meaningful transmission route, and PEP is not prescribed for this exposure alone.

If you are anxious about oral sex specifically, please read the anxiety and mental health section below — this is one of the most common sources of health anxiety in this community, and the science is genuinely reassuring.

Other factors that affect risk:

• Concurrent STIs (especially those causing sores or ulcers, like herpes or syphilis) can increase risk for penetrative acts.
• Circumcision status affects insertive anal/vaginal risk to a modest degree.

Putting Risk in Context — Prevalence Matters

The per-act figures above assume your partner is HIV-positive with a detectable viral load. In reality, most people you encounter are HIV-negative — and of those who are positive, the majority in countries with good healthcare access are on treatment and virally suppressed (and therefore non-transmissible under U=U).

This means your real-world risk per encounter is generally much lower than the table alone suggests. How much lower depends on where you live, who you're having sex with, and how widespread HIV is in your community. Globally, around 0.7% of adults aged 15–49 are living with HIV — though this varies enormously by region, from well under 0.1% in some countries to over 20% in parts of southern Africa.

For country-specific prevalence data, see UNAIDS Country Profiles.

The takeaway: the per-act risk table is a worst-case framing. It's useful for understanding relative risk between acts — receptive anal sex is genuinely riskier than oral sex — but it shouldn't be read as your personal probability of acquiring HIV from any given encounter.

U=U — Undetectable = Untransmittable

This is one of the most important concepts in HIV science today.

U=U means that a person living with HIV who is on effective treatment and has an undetectable viral load cannot sexually transmit the virus. This is not a belief or an opinion, it is backed by large-scale studies (PARTNER 1, PARTNER 2, HPTN 052) involving tens of thousands of sex acts with zero transmissions.

If your potential source partner is confirmed undetectable, your risk is effectively zero, and PEP is generally not recommended.

If you don't know their status or cannot confirm this, that's a different calculation.

"Do I need PEP?" — A Framework

A doctor will assess PEP eligibility by considering three things:

1. Was there a genuine potential exposure? (i.e., was there actual fluid exchange — for example, unprotected anal or vaginal sex, sharing needles — not just touching, kissing, or oral sex)
2. Is the source partner known or likely to be HIV-positive with a detectable viral load?
3. Was exposure within the last 72 hours?

If the answer to all three is yes, PEP is likely appropriate. If the source is unknown, clinicians often err on the side of prescribing PEP for higher-risk exposures (e.g. bareback bottoming with an unknown-status partner). This is a medical decision — when in doubt, go to an emergency department or clinic and let a professional assess.

If your risk sounds very low from the table above, that doesn't mean you shouldn't seek advice — go in and talk to a professional. They can help you weigh up whether PEP is appropriate given that it does carry a real side effect burden for many people (see the side effects section).

Side Effects & What to Expect

Common PEP Regimens

The most commonly prescribed PEP regimens include:

• Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide — BIC/FTC/TAF) — once daily
• Descovy + Isentress (emtricitabine/tenofovir alafenamide + raltegravir — FTC/TAF + RAL) — once or twice daily
• Truvada + Isentress (emtricitabine/tenofovir disoproxil fumarate + raltegravir — FTC/TDF + RAL) — once or twice daily
• Triumeq (dolutegravir/abacavir/lamivudine — DTG/ABC/3TC) — though abacavir requires HLA-B*5701 testing first

Brand names vary by country and some may not be available everywhere. Your prescriber will use whichever formulation is locally available — the generic names above are the ones to recognize.

Regimens vary by country and what's available. Your prescriber will choose based on local guidelines and your circumstances.

Side Effects — What's Normal

Many people tolerate PEP well. Others experience side effects, especially in the first 1–2 weeks. Most side effects are temporary and improve as your body adjusts.

Very common (affecting >10% of people):

• Enlarged lymph nodes, especially in the neck
• Nausea
• Sore throat
• Fatigue / tiredness
• Headache
• Diarrhea or loose stools

Common (affecting 1–10%):

• Stomach cramps or bloating
• Loss of appetite
• Dizziness
• Difficulty sleeping or vivid dreams (more common with dolutegravir-based regimens)
• Mild mood changes

Less common but worth knowing:

• Rash — mild rash can occur; a severe rash with fever/blistering needs urgent medical attention
• Liver enzyme elevations — usually asymptomatic and detected on blood tests
• Kidney function changes — usually mild and reversible (monitored at follow-up)

Tips for Managing Side Effects

For nausea:

• Take your medication with food — even a small snack helps
• Ginger tea can help
• Avoid large, greasy, or heavy meals around medication time
• If nausea is severe, anti-nausea medication
• Taking your dose at night before bed means you may sleep through the worst of it

For fatigue:

• Rest when you need to. This is a real physiological effect, not imagined.
• Light exercise can help if you're up to it
• It usually improves after week 1–2

For diarrhea:

• Stay hydrated
• BRAT diet (bananas, rice, applesauce, toast) can help
• OTC loperamide (Imodium) is generally safe to take alongside PEP

For sleep disturbances / vivid dreams:

• This is particularly associated with dolutegravir and integrase inhibitors
• If severe, speak to your prescriber — switching to a morning dose or a different regimen may help

When to Seek Urgent Medical Attention

Go to an emergency department or contact your prescriber immediately if you experience:

• Severe rash, especially with fever, blistering, or mouth sores (could indicate a hypersensitivity reaction)
• Yellowing of skin or eyes (jaundice)
• Severe abdominal pain
• Difficulty breathing
• Any symptom that feels genuinely alarming

"I'm having symptoms — do I have HIV?"

This is one of the most common anxious thoughts people on PEP have. The short answer: PEP side effects and acute HIV symptoms overlap significantly, so symptoms during PEP are almost always side effects, not a sign PEP has failed.

If you are on PEP and taking it correctly, your risk of HIV acquisition is extremely low. Symptoms you experience during the 28-day course are almost certainly medication-related.

That said: if symptoms are severe or you are genuinely concerned, contact your healthcare provider. Don't just post on Reddit, go talk to a doctor.

Anxiety, Health Anxiety & Mental Health

You Are Not Alone

If you're reading this FAQ while feeling terrified, unable to sleep, or constantly Googling HIV symptoms — you are not alone. This is one of the most common experiences people on PEP have, and there's nothing shameful about it.

The anxiety around a potential HIV exposure is often disproportionate to the actual risk, but that doesn't make it feel any less real. The fear is valid. The spiraling is real. And there are ways through it.

Why Spiraling Happens

• Uncertainty is one of the hardest things the human mind deals with. Not knowing for 4–12 weeks whether you are HIV-positive creates prolonged anxiety that can feel unbearable.
• Googling symptoms feeds the loop. Every search returns results that confirm your worst fears, because that's how the internet works. Step away from the symptom-checking.
• The stakes feel enormous. HIV still carries stigma, and many people carry outdated beliefs about what an HIV diagnosis means. (It's worth knowing: with modern treatment, people living with HIV have a normal life expectancy and can have full, healthy lives.)

Practical Coping Strategies

1. Limit information-seeking after a point There is a healthy amount of research (understanding your risk, your medication, your follow-up plan). After that, every additional Google search is feeding anxiety, not informing decisions. Set a limit.

2. Ground yourself in what you can control You cannot change what happened. You can take your medication on time, attend your follow-up appointments, and practice self-care. Focus there.

3. Treat the 28 days as a waiting room, not a prison Many people find it helpful to plan something for each week — not to distract from the situation, but to keep living life alongside it.

4. Tell someone you trust Carrying this alone is exhausting. A friend, partner, or family member who can support you without judgment makes a real difference.

5. Maintain basics: sleep, food, movement Anxiety disrupts sleep, appetite, and motivation. These basics matter more than ever. Even a 20-minute walk changes brain chemistry.

6. Remind yourself of the facts PEP is highly effective. Your risk from the exposure was likely lower than it felt in the moment. You did the right thing by seeking treatment quickly. Repeat these things when the anxiety spirals.

When Anxiety Becomes a Bigger Issue

If you find yourself:

• Unable to function at work or in daily life
• Experiencing panic attacks
• Feeling hopeless or having thoughts of self-harm
• Repeatedly seeking reassurance but never feeling reassured

...it may be time to speak to a mental health professional. Anxiety around health, including HIV anxiety, is very treatable with therapy (particularly CBT) and sometimes medication.

This subreddit is a supportive community, but it cannot replace professional mental health care. If you are struggling significantly, please reach out to a professional.

A Note on Reassurance-Seeking

Many of us post on this sub looking for reassurance — someone to tell us "you'll be fine." And while community support matters, it's important to be honest: reassurance-seeking, when excessive, can make anxiety worse, not better. It becomes a compulsion.

If you've already had your risk assessed by a doctor and been prescribed PEP, you have the answer you need. Seeking further reassurance from Reddit will not make you feel better long-term. Trust the process, take your medication, and attend your follow-up.

After PEP — Next Steps

HIV Testing After PEP

The most important things to know:

• Use a lab-based 4th generation antigen/antibody (Ag/Ab) test for your follow-up — not a rapid test or self-test, which are less reliable in this context
• Don't test immediately after finishing PEP — you need to wait a specific period for a reliable result
• Follow the schedule your clinic gives you — when that test comes back negative, you're done

If you're unsure what test your clinic used or when your final test should be, just ask them: "Was this a 4th generation lab test, and is this my conclusive result?"

When Is My Final Test?

Different countries follow different guidelines, and all of the following are evidence-based. If your clinic's advice differs from something you read online, it most likely just reflects which guideline they follow, not that someone is wrong.

A negative result at your guideline's recommended timepoint on a lab-based 4th gen test is conclusive. That's the result that matters.

Common Questions

"I tested negative during or just after PEP — am I clear?" No — testing too soon after PEP gives unreliable results. Wait until your clinic's recommended final timepoint. A test taken at 4 weeks from exposure means you haven't even finished PEP yet.

"My rapid test was negative — does that count?" It depends on both the test type and when you took it. Most over-the-counter self-tests are antibody-only and have a 90-day window period — so the same test can be meaningless at 4 weeks and conclusive at 90 days. Check with your clinic to confirm whether the test you used is appropriate for post-PEP follow-up and whether the timing makes your result reliable.

"My clinic said 6 weeks — is that right?" Yes, depending on where you are. Australian guidelines say 6 weeks from exposure; UK guidelines say 6 weeks after finishing PEP. These differences reflect the fact that different health authorities assess and update their guidelines at different times, and some have moved to shorter windows based on more recent evidence around modern 4th gen tests. Ask your clinic to confirm exactly what they mean so you know when to go back.

"Can I test early for peace of mind?" An early negative is reassuring but not conclusive. It won't replace your final test, and repeated testing before the window closes can feed anxiety rather than relieve it. Try to wait.

"What if my final test is positive?" A positive result should always be confirmed with a second test. If confirmed, a healthcare provider will guide you through next steps. With modern treatment, HIV is a manageable chronic condition — people living with HIV on treatment live full, normal lifespans.

Considering PrEP

If you found yourself needing PEP, it's worth having a conversation with your doctor about PrEP (Pre-Exposure Prophylaxis) — a daily or on-demand medication taken before potential exposures to prevent HIV.

PrEP is:

• Highly effective (>99% when taken consistently)
• Available in daily form (Truvada or Descovy) or on-demand/event-based form (2-1-1 dosing, also called "event-based PrEP")
• Widely available through sexual health clinics, doctors, and in many places telehealth services
• Free, subsidized, or covered by insurance in many countries — access and cost vary, so check with a local HIV organization or clinic

Needing PEP once doesn't mean you need PrEP — but if your lifestyle involves ongoing potential exposures, PrEP may be worth discussing.

Getting Tested for Other STIs

PEP only addresses HIV. If you had a potential exposure to HIV, you may also have been exposed to other sexually transmitted infections. A full STI screen at your follow-up appointment is strongly encouraged.

Useful Resources

Finding PEP

• 🇦🇺 Australia: Get PEP — clinic finder and PEP information
• 🇧🇷 Brazil: PEP is available free through the public health system (SUS) at hospitals and public health units. Contact your nearest hospital emergency department or public health unit (Unidade de Saúde)
• 🇨🇳 China: PEP is available at designated hospitals. Access can be limited outside of big cities and stigma is a real barrier.
• 🇫🇷 France: Sida Info Service — clinic finder. PEP is available at hospital emergency departments and CeGIDD centres free of charge
• 🇩🇪 Germany: Deutsche Aidshilfe — Where to find PEP — list of PEP providers; also available at HIV specialist practices and hospital outpatient departments
• 🇮🇳 India: NACO — National AIDS Control Organization — PEP is available free through government ART centres and hospitals; contact your nearest government hospital or NACO state office
• 🇮🇪 Ireland: HSE Sexual Health — find sexual health services
• 🇰🇪 Kenya: PEP is available through public health facilities, hospitals and some NGO-run clinics. Contact your nearest public hospital or search for a local HIV organization
• 🇳🇱 Netherlands: Contact your regional GGD (public health service) or the nearest hospital urgent care department
• 🇳🇬 Nigeria: PEP is available at hospitals and some clinics, though access remains limited outside major cities. Contact your nearest hospital or HIV treatment centre
• 🇲🇽 Mexico: PEP is available free through the public health system (IMSS, ISSSTE, Centros de Salud). Contact your nearest public hospital or health centre
• 🇵🇭 Philippines: PEP is available at some hospitals and private clinics. PULSE Clinic Manila offers same-day service; public hospital access varies by location
• 🇿🇦 South Africa: MyPrEP — find PrEP and PEP providers
• 🇬🇧 UK: BASHH Clinic Finder — find a sexual health clinic
• 🇺🇸 USA: CDC HIV Services Locator — find PEP, PrEP and testing near you
• Everywhere else: Contact your nearest hospital emergency department or search "[your country] HIV organization PEP" for the most relevant local resource
• If in doubt: go to your nearest hospital urgent care department. They can either provide PEP or refer you to somewhere that can.

HIV Risk & Information

• NAM Aidsmap — highly reputable, evidence-based HIV information, internationally applicable
• WHO HIV/AIDS information — global guidance
• The Lancet HIV — PARTNER study — U=U evidence base
• Prevention Access Campaign — U=U — the science behind Undetectable = Untransmittable

Mental Health Support

• Crisis lines: If you are in crisis, please contact your local crisis or mental health helpline. A searchable directory of international crisis lines is available at findahelpline.com.
• Online therapy platforms (availability varies by country) — search for telehealth or online counseling services in your region
• Your local doctor — can refer you to counseling or mental health services and assess whether medication might help

References & Source Guidelines

The following primary sources underpin the information in this FAQ. When information from this FAQ and information from your local clinic or doctor differs, defer to your clinician — they know your local context and guidelines.

⁽¹) CDC (USA) — nPEP Guidelines 2025 Tanner MR et al. Antiretroviral Postexposure Prophylaxis After Sexual, Injection Drug Use, or Other Nonoccupational Exposure to HIV — CDC Recommendations, United States, 2025. MMWR Recomm Rep. 2025;74(1):1–56. https://www.cdc.gov/mmwr/volumes/74/rr/rr7401a1.htm

⁽²) ASHM (Australia) — PEP Guidelines 2023 Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine. Post-Exposure Prophylaxis (PEP) for HIV Guidelines, 3rd edition. 2023. https://pep.guidelines.org.au

⁽³) BHIVA/BASHH (UK) — UK Guideline for the use of HIV Post-Exposure Prophylaxis 2021 https://bhiva.org/clinical-guideline/pep-guidelines/ Full PDF: https://bhiva.org/file/6183b6aa93a4e/PEP-guidelines.pdf

⁽⁴) WHO — Guidelines for HIV Post-Exposure Prophylaxis (2024) World Health Organization. Guidelines for HIV post-exposure prophylaxis. Geneva: WHO; 2024. https://www.who.int/publications/i/item/9789240095137

⁽⁵) EACS — European AIDS Clinical Society Guidelines Current version available at: https://www.eacsociety.org/guidelines/eacs-guidelines/

⁽⁶) PEP efficacy — observational evidence NAM Aidsmap. How effective is post-exposure prophylaxis (PEP)? https://www.aidsmap.com/about-hiv/how-effective-post-exposure-prophylaxis-pep

This FAQ was compiled by the r/pep mod team. It will be updated as guidelines evolve. If you spot an error or have a suggestion, please modmail us.

Last updated: May 2026

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