The best time to start PrEP for a Thailand trip is far enough ahead that it is fully working by your first night out. With daily PrEP, that means about 7 days before receptive anal sex, or about 21 days before receptive vaginal or front-hole sex.
If you have less time than that, you still have options. This guide works back from your flight date, helps you count the pills you need and explains how to start PrEP in Pattaya if you land without any.
For the bigger picture on access and the law, see our main guide to PrEP in Thailand for visitors.
Count back from your first night out
The key date isn't your flight. It is the first time you might have sex, which for many people is the first or second night in Pattaya.
Find your own situation below. If your dates are tight, the PrEP planner turns them into real calendar days.
Three weeks or more before you fly
You have the easiest path. See a doctor at home, have the start-up tests and begin daily PrEP.
By the time you land, daily PrEP will have built up to full protection for any type of sex. You also get a chance to settle into the routine before the holiday starts.
One to three weeks before you fly
Daily PrEP started now should reach full protection for receptive anal sex before you arrive. For vaginal or front-hole sex, you may need to wait until a few days into the trip, so use condoms until you reach day 21.
Our guide to how long PrEP takes to work explains why the two timelines differ.
Less than a week before you fly
You can still get started. If you only have anal sex and don't have hepatitis B, on-demand 2-1-1 PrEP may suit you, because protection comes from a double dose taken 2–24 hours before sex.
Otherwise, start daily PrEP as soon as you can and use condoms until you reach your protection date. A doctor will assess which option fits you.
How much PrEP to take on holiday
Running short abroad is stressful, so pack generously. Here is a simple way to count.
- Lead-in days: the days you take PrEP before you leave.
- Trip days: every day you are away, travel days included.
- After days: the days your doctor advises after your last sex.
- Spare days: about five, for delays and lost pills.
Rough daily PrEP pill counts by trip length
| Trip length | Start 7 days before | Start 21 days before |
|---|---|---|
| 1 week | About 26 pills | About 40 pills |
| 2 weeks | About 33 pills | About 47 pills |
| 3 weeks | About 40 pills | About 54 pills |
| 4 weeks | About 47 pills | About 61 pills |
The table assumes 7 days after your last sex and five spare days. Your doctor may advise a different number of days after you stop, so check before you pack.
Counting for 2-1-1
On-demand PrEP uses fewer pills, but only if your plans are predictable. One single night of sex uses four pills; a long weekend with sex on three nights in a row uses six.
Pack at least two full sets more than you think you'll need. Weekends in Pattaya rarely go exactly to plan.
Starting PrEP after you land in Pattaya
Many travellers find it easier to start PrEP here than at home. Many travellers start within their first days in Pattaya, once they have had the start-up tests.
A doctor will run the start-up checks, including an HIV test, kidney function and hepatitis B. Our page on the tests before PrEP explains each one.
The trade-off is timing. If you start on day one of your holiday, you will not be fully protected on day one, so plan the first week with condoms or a 2-1-1 start if it suits you.
Staying on track during the trip
Holidays break routines. Long flights, late nights and new time zones are when doses get missed.
Time zones
Once you arrive, take your pill at your usual clock time in Thai time. One dose gap will be a little longer or shorter than 24 hours, and that is fine for daily PrEP.
Late nights and alcohol
Alcohol does not stop PrEP working, but it makes forgetting more likely. Take your pill with breakfast, not "later tonight". Our guide to PrEP and alcohol has more tips.
If you miss a dose or run out
One late or missed pill is rarely a disaster. See what to do if you miss a PrEP dose for step-by-step advice.
If you run out, a clinic can test you and give you a new supply. If you had sex while unprotected in the last 72 hours, you may need PEP, not PrEP, so act straight away.
Your trip timeline at a glance
What to do before, during and after
| When | What to do |
|---|---|
| Before you fly | Tests, start PrEP, pack pills plus spares |
| First days in Thailand | Keep your usual dose time, use condoms until protected |
| During the trip | Daily dose with breakfast, carry condoms |
| Last days | Keep taking PrEP as advised after your last sex |
| Back home | HIV test and STI check at your usual service |
PrEP does not prevent other STIs, so an STI check after a holiday is a good habit. The CDC's travel health advice for Thailand also covers vaccines and other health planning before you go.
Getting PrEP in Pattaya
If you are staying in central Pattaya, Jomtien or Naklua, starting or topping up PrEP is simple. Read our step-by-step guide to getting PrEP in Pattaya to see how a first visit works, and check the PrEP prices page for current costs.
Staying a month or longer? You can collect a further supply here after a quick HIV test, rather than flying in with a suitcase full of pills. That keeps your 3-monthly follow-up on track too, even when you are far from your usual clinic at home.
Send us your arrival date and how long you are staying, and we'll suggest the best start date for you. Message us on LINE or WhatsApp to plan your PrEP before or after you land.
Frequently asked questions
How long before my Thailand trip should I start PrEP?
About 7 days before receptive anal sex or about 21 days before receptive vaginal or front-hole sex, if you are using daily PrEP. Starting three weeks ahead covers both.
Can I start PrEP when I arrive in Thailand?
Yes. A clinic in Pattaya can test you and start you on PrEP, but protection takes time to build, so plan your first days with that in mind.
How many PrEP pills should I bring on holiday?
Add your lead-in days, trip days, the days advised after your last sex and about five spares. For a two-week trip on daily PrEP, that is often 33 to 47 pills.
Is 2-1-1 PrEP good for a holiday?
It can be, for people who only have anal sex and don't have hepatitis B. It is not suitable for vaginal or front-hole sex or for people taking oestradiol.
Do I need an HIV test after my trip?
Yes. Everyone on PrEP should have an HIV test every 3 months, and an STI check after a holiday is sensible.