Sexual Health · Medication Guide
PEP in Thailand
PEP is emergency HIV medicine taken after a possible exposure, and it only works if you start within 72 hours. This guide covers what it is, how well it works, its side effects, and how to get it fast and legally in Bangkok. Reviewed by a licensed physician at a MOPH-registered men's health clinic.
- Must start within 72 hours
- Thai FDA registered · prescription only
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Medically reviewed by Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic
Last reviewed
11 July 2026
72 h
Window to start PEP
the sooner after exposure, the better
28
Days of daily tablets
a full course, taken every day
81%
Lower risk of HIV
early PEP, occupational-exposure study
3
Follow-up HIV tests
at baseline, 4–6 weeks, and 3 months
Key takeaways
PEP is a 28-day course of antiretroviral medicine that can prevent HIV after a possible exposure, but only if it is started fast.
It must begin within 72 hours of exposure, and sooner is better. Treat a possible exposure as a medical emergency, not something to sleep on.
In Thailand PEP is prescription-only and requires an HIV test first: you must be HIV-negative to start. It is not sold over the counter.
PEP greatly lowers risk but is not a guarantee, and it is not a substitute for PrEP or condoms. A doctor chooses the regimen and arranges follow-up testing.
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What PEP is & how it works
PEP stands for post-exposure prophylaxis: a short course of HIV medicines taken after a possible exposure to stop the virus from establishing a permanent infection. It is emergency prevention, not a routine treatment, and it is used when someone who is HIV-negative may have just come into contact with the virus.
It works by racing the virus. After exposure, HIV needs time to copy itself and spread from the initial site into the lymph nodes and bloodstream. The medicines block the enzymes HIV uses to replicate, so if they are started early enough, exposed cells die off before a lasting infection can take hold. Once the virus has spread body-wide, PEP can no longer stop it, which is why the 72-hour window is a hard limit.
Each regimen combines three drugs that hit different steps of the viral lifecycle: an integrase inhibitor (dolutegravir or bictegravir) plus two reverse-transcriptase inhibitors (emtricitabine and tenofovir alafenamide), taken as a single daily tablet. Whether PEP is appropriate, and which regimen fits your history, is what the doctor's assessment is for.
Exposure happens
HIV enters through blood or mucosal tissue and starts infecting local immune cells.
A short window opens
For roughly 72 hours the virus has not yet spread body-wide.¹
The drugs block replication
Integrase and reverse-transcriptase inhibitors stop HIV from copying itself.
Infection is prevented
With replication halted, exposed cells die off before permanent infection sets in.²
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Getting PEP in Thailand
Thai FDA status
The antiretrovirals used for PEP are registered with the Thai FDA and are prescription-only. The dolutegravir-based single tablet is sold in Thailand under brands such as Kocitaf. PEP is recommended in Thailand's national HIV guidelines and provided through hospitals and licensed clinics.³
How Menscape dispenses it
A licensed physician confirms you are still inside the 72-hour window and orders a rapid HIV test to confirm you are negative before starting. If PEP is suitable, it is prescribed and dispensed by a licensed pharmacy the same day, for pickup or delivery.
Don't self-source online
PEP is an emergency, but buying antiretrovirals from unlicensed online sellers is illegal, and counterfeits are common. Starting the wrong drugs, the wrong dose, or an incomplete course can fail and drive resistance. If you cannot reach a clinic in time, go to a hospital emergency department.
Thai FDA warning. The regulator has repeatedly warned against buying prescription medicines from unlicensed online sellers, where counterfeit products are common and nobody is accountable for what you receive.⁶
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Does it work? The evidence
PEP works, but its effectiveness depends almost entirely on how fast you start and whether you finish the course. The strongest human evidence comes from a 1997 case-control study of healthcare workers with needlestick injuries, where taking zidovudine after exposure was linked to an 81% lower risk of HIV infection. There has never been a randomised placebo-controlled trial, because it would be unethical to withhold PEP, so an exact modern figure does not exist.
Today's integrase-inhibitor regimens (dolutegravir or bictegravir with emtricitabine and tenofovir alafenamide) are far better tolerated than the older drugs used in that study, so more people complete all 28 days, which is the single biggest driver of success. When PEP fails, it is almost always linked to a late start, missed doses, or stopping early.
81%
Lower HIV risk
early PEP in an occupational-exposure study
72 h
Start window
effectiveness falls sharply after this
Cardo et al., a case-control study of occupational HIV exposure. There is no placebo-controlled PEP trial; individual risk depends on the exposure.
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Side effects & who shouldn't take it
Common side effects
Nausea, headache, diarrhoea, tiredness and trouble sleeping, usually mild and mostly in the first days. Modern single-tablet regimens are much gentler than older PEP, and anti-nausea medicine can help you finish the course.
Serious or rare
Hypersensitivity reactions are rare but need urgent review. Tenofovir can affect kidney function, and weight gain is reported. If you have hepatitis B, stopping these drugs can trigger a liver flare, so tell your doctor.
Not suitable for
PEP is only for people who are HIV-negative at the time of exposure, so a baseline test is mandatory. It needs dose review in significant kidney disease, and anyone who is pregnant or may become pregnant should discuss the regimen with the doctor first.
Interactions & warnings
Dolutegravir and bictegravir interact with antacids, calcium and iron supplements, some seizure and TB medicines, and metformin. Tell your doctor every medicine and supplement you take, and complete all 28 days: stopping early risks both failure and drug resistance.
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Alternatives & combinations
Ongoing prevention · after PEP
PrEP
If your risk is repeated or ongoing, PrEP (a daily tablet taken before exposure) is the long-term way to prevent HIV. Many people move straight from a PEP course onto PrEP once the 28 days are done.
Alternative regimen · same class
Bictegravir-based single tablet
A second single-tablet option with a high barrier to resistance. The doctor chooses between it and the dolutegravir-based tablet based on your history and any other medicines you take.
Same visit · different risk
STI testing & condoms
PEP protects against HIV only, not other sexually transmitted infections. After a possible exposure, full STI screening and condom use remain essential parts of staying safe.
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How PEP works at Menscape
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Possible exposure? Speak to a doctor today.
Message us on WhatsApp or LINE
Tell us when the exposure happened and answer a short health questionnaire. Because PEP is time-critical, flagging it as urgent means you are seen the same day. It is PDPA-protected and confidential.
Same-day doctor consultation & HIV test
A licensed Thai physician reviews your exposure and confirms you are inside the 72-hour window. A rapid HIV test confirms you are negative before anything is prescribed.
Prescription, if suitable
If PEP is appropriate, the doctor prescribes a 28-day single-tablet regimen, dispensed by a licensed pharmacy for same-day pickup or delivery so you can start without delay.
Follow-up & testing
Check-ins during the course and repeat HIV tests at 4–6 weeks and 3 months. If your risk is ongoing, your doctor can plan a move onto PrEP.
The doctor decides. PEP is only appropriate within 72 hours of exposure and for people who are HIV-negative. If PEP is not right for you, the doctor will explain why and what to do next.
Medically reviewed by
Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic, Bangkok
“With PEP, time is the treatment. If you think you have been exposed, come in the same day, because every hour we lose makes the medicine less likely to work.”
- Reviewed
- 11 July 2026
- Next review
- January 2027
- Editorial standard
- Each guide is checked against the Thai FDA label and the primary literature, then reviewed by a licensed physician.
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Frequently asked questions
Can I buy PEP over the counter in Thailand?
No. The antiretrovirals used for PEP are prescription-only, and you need an HIV test before starting, so PEP always involves a doctor. If you may have been exposed, contact a clinic or hospital straight away rather than trying to source it yourself.
How quickly do I need to start PEP?
Within 72 hours of the exposure, and the sooner the better. After 72 hours the virus has usually spread too far for PEP to work. Treat a possible exposure as an emergency and get seen the same day.
How long do I take it for?
A full 28 days, one tablet once a day. Finishing the entire course is the single most important factor in whether it works. Stopping early risks both failure and drug resistance.
What counts as a possible HIV exposure?
Condomless sex, a broken condom, sharing needles, a needlestick injury, or sexual assault are common reasons to consider PEP. If you are unsure whether your situation qualifies, get assessed and let a doctor decide.
Does PEP always work?
No. PEP greatly lowers the risk of HIV but is not a guarantee, especially if it is started late or doses are missed. Follow-up HIV testing at 4–6 weeks and 3 months confirms your status.
What's the difference between PEP and PrEP?
PEP is emergency treatment taken after a possible exposure, as a 28-day course. PrEP is taken before and on an ongoing basis to prevent HIV in people with continuing risk. If your risk is ongoing, ask your doctor about moving onto PrEP.
Can I get PEP as an expat or tourist in Thailand?
Yes. No Thai residency is required; bring ID and any medical history you have. Because of the 72-hour window, go to the nearest clinic or hospital emergency department without delay if you may have been exposed.
Is the consultation confidential?
Yes. Your consultation and HIV test are confidential and PDPA-protected. Nothing is shared without your consent, and you can be seen by video call or in clinic at Asoke.
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References
1. World Health Organization. Consolidated guidelines on HIV prevention, testing, treatment: post-exposure prophylaxis for HIV. WHO. 2021.
2. Cardo DM, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. N Engl J Med. 1997;337(21):1485-1490.
3. Department of Disease Control, Ministry of Public Health. Thailand National Guidelines on HIV/AIDS Treatment and Prevention. MOPH. 2021/2022.
4. U.S. CDC. Updated Guidelines for Antiretroviral Postexposure Prophylaxis After Sexual, Injection Drug Use, or Other Nonoccupational Exposure to HIV. CDC. 2016.
5. U.S. FDA prescribing information for Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) and dolutegravir-based combination tablets. Accessed July 2026.
6. Thai Food and Drug Administration. Drug registration database and consumer warnings, ndi.fda.moph.go.th and oryor.com. Accessed July 2026.
7. British HIV Association (BHIVA). UK guideline for the use of HIV post-exposure prophylaxis. 2021.
This guide is educational information, not medical advice. PEP is a prescription medicine and a time-critical decision: if you may have been exposed to HIV, seek care immediately. Only a licensed physician can prescribe and monitor it.
This guide is part of the Menscape sexual-health library
Explore the condition hubPossible HIV exposure? Ask a doctor today, not tomorrow.
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