Koh Samui has quietly become a place where people stay a while. Remote workers rent villas in Bophut for the season, divers spend months between here and Koh Tao, and plenty of visitors come for two weeks and stay for six. Longer stays bring new friends, new relationships and, often, sex that was not part of the original plan.
If that sounds familiar, PrEP is worth knowing about. It is a simple, highly effective way to prevent HIV before any exposure happens, and starting it on the island is easier than most people expect.
Key points
- PrEP is a tablet that prevents HIV, taken daily or, for some people, around sex.
- Taken as prescribed, it reduces the risk of getting HIV from sex by about 99%.
- You need an HIV test and a kidney check before starting, then follow-up tests about every 3 months.
- PrEP does not protect against other STIs, so regular screening is part of the routine.
Who PrEP suits on a long stay
PrEP is for anyone who might be exposed to HIV. On Samui, we tend to see it chosen by:
- Remote workers and long-stay visitors who are dating or meeting new partners
- Gay, bisexual and other men who have sex with men, who are statistically at higher risk
- People whose partner is living with HIV and not yet undetectable
- Anyone who has needed PEP before and does not want to rely on emergencies
- People who use condoms most of the time, but not always
There is no need to justify it. Wanting to be protected is reason enough.
Starting PrEP on the island
Starting PrEP is a single visit for most people:
Step 1: HIV test
PrEP is only for people who are HIV negative. If you have had a possible exposure in the last 72 hours, you need PEP first, not PrEP.
Step 2: Kidney check
PrEP medicines are processed by the kidneys, so a simple blood test checks they are working normally.
Step 3: Hepatitis B check
This matters especially if you are considering on-demand dosing, which is not suitable for people with hepatitis B.
Step 4: Choose your routine and get your supply
The doctor goes through daily and on-demand options with you, and you leave with your tablets and a date for your next check.
Thinking about PrEP?Walk in any day without a booking, or message first so the doctor is ready.
Daily or on-demand: which suits island life?
| Daily PrEP | On-demand PrEP (2-1-1) | |
|---|---|---|
| How to take it | One tablet every day | 2 tablets before sex, then 1 a day for 2 days |
| Who it is for | Everyone | Cisgender men having anal sex only |
| Time to protection | About 7 days for anal sex, 21 days for vaginal sex | From the double dose, taken 2 to 24 hours before sex |
| Best if | Sex is frequent or unpredictable | Sex is occasional and can be planned |
| Not suitable if | Kidney problems | Hepatitis B, vaginal sex, trans women on hormones |
Many long-stayers find daily PrEP simpler. Island social life is rarely predictable, and a fixed daily routine removes the need to plan ahead. On-demand works well for men who have sex less often and can reliably take the first double dose in advance.
Staying on PrEP: the 3-month routine
PrEP is not a one-off. Roughly every 3 months you will need:
- An HIV test, to make sure you are still negative
- STI tests, because PrEP does not protect against gonorrhoea, chlamydia or syphilis
- A kidney check, usually at least once a year, or more often depending on your age and health
- A new supply
If you are staying on Samui for a season, you can do these check-ups here. Set a reminder in your calendar on the day you start.
Moving on: other islands, Bangkok, or home
Long stays rarely end in one place. If you are heading to Koh Phangan, Koh Tao or Bangkok next, PrEP travels easily. Keep enough supply for the trip, carry tablets in your hand luggage and keep your routine across time zones. If you are crossing several time zones, aim to keep the gap between doses close to 24 hours and do not double up.
When you go home, PrEP is available through sexual health services in many countries. Ask for an English summary of your tests and prescription so your doctor at home can continue it smoothly.
Stopping PrEP safely
If your situation changes and you no longer need PrEP, do not just stop the day you leave. For daily PrEP, the general advice is to keep taking it for a period after your last possible exposure; for on-demand, finish the two post-sex doses. Exactly how long depends on the type of sex you have, so confirm with the doctor before you stop.
Moving on soon?Tell the doctor your travel dates and they will help you plan supply and next steps at home.
Frequently asked questions
Can I start PrEP on the same day?
Usually, yes, once your HIV test is negative. Some results, like kidney function, may come back later and be reviewed then.
Does PrEP have side effects?
Most people have none. A small number notice mild nausea or headaches in the first few weeks, which usually pass.
Can I drink and still be protected?
Yes. Alcohol does not reduce PrEP’s effectiveness. The risk is forgetting doses after late nights, so keep a spare tablet with you.
Does PrEP replace condoms?
PrEP is highly effective against HIV on its own. Condoms add protection against other STIs. Many people use both, some choose PrEP alone with regular STI testing.