If you need PEP after the Full Moon Party, the key rule is simple: start within 72 hours, and the sooner the better. You can get medical help on Koh Phangan itself, or take a short boat to Koh Samui — what matters most is not waiting.
This guide explains your options, rough travel times and a clear plan for the next three days. It is about health and safety only, and nobody here will judge you.
Is there an HIV risk after the Full Moon Party?
The party itself does not carry HIV risk. The risk comes from what can happen around it: sex without a condom, a condom that broke, or not remembering what happened.
Alcohol and drugs make it harder to plan and easier to take risks. The UK government's Thailand travel advice on safety and security also warns that drink spiking and assaults happen in tourist areas, especially at full moon parties.
When PEP may be worth asking about
- You had vaginal or anal sex without a condom, or the condom broke or slipped
- You don't know your partner's HIV status
- You can't remember clearly and worry something happened
- You think you may have been assaulted
A doctor will assess your situation. If PEP is not needed, you will still leave with a clear plan for testing.
Why the 72-hour window matters
PEP is a 28-day course of HIV medicines taken after a possible exposure. It works best when started within hours, and it should not be started later than 72 hours.
The party usually ends in the early morning. That means the clock has often been running for several hours before you wake up. Treat the morning after as the time to act, not the time to wait and see.
For more on the first steps, see our step-by-step plan for the first 72 hours after a condom breaks. Every hour you save gives PEP a better chance to work.
PEP on Koh Phangan or travel to Koh Samui?
Koh Phangan has its own medical facilities, including a government hospital and private clinics. If you are feeling unwell or can't travel, getting seen on Phangan is a good choice.
Some people prefer to cross to Samui, for example if they are already heading there or want follow-up care on a bigger island. Either way is fine. The best option is the one that gets you seen soonest.
Koh Phangan vs Koh Samui for PEP
| Option | Pros | Cons | Time to get seen |
|---|---|---|---|
| Stay on Koh Phangan | No boat needed; fastest if you're unwell | Clinics can be busy after the party | Often the same morning |
| Travel to Koh Samui | Wider choice of clinics; easy for follow-up and flights home | Adds boat and taxi time | Usually a few hours in total |
| Wait until you get home | Familiar health system | High risk of missing 72 hours | Often too late |
Boat options from Koh Phangan to Koh Samui
Several boat companies run between the islands every day. Most leave from Thong Sala, while some small boats leave from Haad Rin, near the party beach.
Times below are rough ranges only. Schedules change with seasons and weather, so always check current timetables with the boat company or your accommodation.
Approximate boat options to Samui (check current timetables)
| Boat type | Typical departure | Approximate crossing | Good to know |
|---|---|---|---|
| High-speed catamaran | Thong Sala | About 20–45 minutes | Several daytime sailings |
| Standard ferry | Thong Sala | About 45–60 minutes | Cheaper, slower |
| Small local boat | Haad Rin | About 45–60 minutes | Handy from the party beach |
| Private speedboat | Various piers | Varies by route and sea | Most expensive; ask about safety |
Add time for a taxi to the pier on Phangan and from the pier on Samui. Boats mostly run in daylight, and rough seas can cause delays or cancellations.
Your 72-hour plan after the party
Use this timeline to stay on track, even if you feel rough.
72-hour planning timeline
| When | What to do |
|---|---|
| As soon as you wake up | Drink water, eat something, and message a doctor |
| Within the first few hours | See a clinic on Phangan, or catch the next boat to Samui |
| At the clinic | Baseline HIV test and a doctor's assessment; start PEP if advised |
| Same day | Set a daily alarm for your PEP |
| Before 72 hours | The absolute latest point to start PEP |
| 4–6 weeks and ~3 months | Follow-up HIV tests, as your doctor advises |
If you were spiked or assaulted
Please get medical help first and take someone you trust with you if you can. A doctor can talk to you about PEP, emergency contraception and STI tests.
Thailand's emergency medical number is 1669. The Tourist Police can help with reporting if you choose to.
Staying safer next time
A few simple steps can lower your risk at any big beach party. None of them are about missing out.
- Carry condoms and lube, and keep them somewhere easy to reach
- Stay with friends and agree a meeting point before the night starts
- Watch your drink and don't accept open drinks from strangers
- Save a clinic's WhatsApp number in your phone before you go out
If you often find yourself needing PEP, daily PrEP may be a better fit. Read about how PEP compares with PrEP and condoms to compare them.
Getting PEP on Koh Samui
If you choose to come to Samui, message us before you get on the boat. We can explain what to bring and help you plan so the crossing doesn't cost extra time.
Our HIV PEP service on Koh Samui includes a baseline test, a doctor's assessment and a 28-day supply if PEP is right for you. Worried about price? Read our guide on how much PEP costs on Koh Samui, or message us for our current price.
Travelling on after Samui
Many party-goers move on within days. That is fine, as long as you take the full course and plan your follow-up tests. Our guide on how to keep taking your 28-day PEP course while you travel covers taking PEP home with you.
You might also want a check for other infections. Our HIV and STI testing on Koh Samui can be done in one visit.
Frequently asked questions
Can I get PEP on Koh Phangan?
Yes, Koh Phangan has medical facilities, and some clinics there can assess you for PEP. If you can't find help quickly, take the boat to Samui.
I can't remember if we used a condom. Should I still ask?
Yes. Tell the doctor what you remember. They will assess the risk with you, without judging you.
Can I wait until I fly home?
Only if you will arrive with plenty of time before 72 hours. Most people won't, so starting PEP in Thailand is usually safer.
Does PEP work if I drank a lot?
Alcohol doesn't stop PEP from working, but a hangover can make it easy to forget doses. Set alarms and take every dose.
Is it too late if it's been more than 72 hours?
PEP is not recommended after 72 hours. See our guide on what to do if it's been more than 72 hours for testing and next steps.
Need PEP after the Full Moon Party?
PEP must be started within 72 hours — the sooner the better. Whether you stay on Phangan or come to Samui, don't wait to ask.
Message a doctor privately on WhatsApp about PEP after the Full Moon Party.