STI Testing for Travellers in Thailand: What to Do, When, and Before You Fly Home

Traveller health guide · 2026

The specific problem for travellers is not access. It is that window periods rarely fit inside a holiday.

By MedEx · Updated September 2026 · Approx. 8-minute read

Quick answer

Travellers face a timing problem: the useful tests often fall due after the flight home. The practical approach is to act immediately on anything time-critical — HIV post-exposure prophylaxis within 72 hours, and assessment of any symptoms — then test what is testable before you leave, usually chlamydia and gonorrhoea PCR from around two weeks, and plan the remaining tests for after you return, particularly HIV and syphilis at 6 and 12 weeks. Results can be reviewed remotely, so leaving Thailand does not mean losing continuity of care.

In this guide

1. What cannot wait
2. What to test before flying home
3. Practical points specific to travellers
4. The schedule once you are home

What cannot wait

HIV post-exposure prophylaxis. If an exposure within the last 72 hours carried HIV risk, PEP is the priority and must start as soon as possible. It is a 28-day course, so starting it in Thailand means planning how to continue it at home — ask for enough supply and documentation before you fly. See MedEx PEP and PrEP services.

Symptoms. Discharge, pain passing urine, a genital ulcer, testicular pain or pelvic pain all warrant assessment now. Symptomatic infection is usually detectable, and treatment prevents both complications and onward transmission. The 24/7 doctor on call covers out-of-hours situations.

Emergency contraception, where relevant, is also time-sensitive.

None of these should be deferred until you get home, and none depends on a test result first.

What to test before flying home

Work backwards from your departure date.

Express options can produce same-day results in Bangkok where the timing is tight — see the same-day results guide.

Practical points specific to travellers

• Sample the right sites. A urine test misses throat and rectal infection. Be explicit about exposure types so the correct swabs are taken — see the STI PCR panel guide.
• Do not self-treat with pharmacy antibiotics. Antibiotics are more readily available in some countries than others, but partial or incorrect treatment can mask infection, complicate later diagnosis and contribute to resistance — a particular concern with gonorrhoea.
• Keep documentation. A written record of what was tested, when, and what treatment was given makes follow-up at home far simpler.
• Consider hepatitis A and B vaccination if not already immune. See MedEx travel vaccination.
• Think about PrEP if ongoing risk is likely, rather than repeating PEP courses. Discussed on the PEP and PrEP page.
• Arrange remote follow-up before you leave so results and treatment do not fall through the gap.

The schedule once you are home

Set the dates before you leave. The usual schedule after a possible exposure:

1. Around 2 weeks: chlamydia and gonorrhoea, if not already done.
2. 6 weeks: HIV fourth-generation test and syphilis serology. Highly reassuring for most people.
3. 12 weeks: repeat HIV and syphilis for a definitive result, and this is also the point at which herpes antibodies would have developed if that is relevant.
4. If PEP was taken: the schedule restarts from the end of the 28-day course.

Full detail is in the window periods guide. If you would rather keep the follow-up with the same team, results can be reviewed by teleconsultation from anywhere, and a broader health checkup can be combined on a return visit.

Frequently asked questions

I am flying home in three days. What should I test now?

If it has been two or more weeks since exposure, chlamydia and gonorrhoea PCR from all relevant sites is worth doing before you leave, along with baseline HIV, syphilis and hepatitis testing after a higher-risk exposure. Any ulcer should be swabbed before it heals.

Can I start PEP in Thailand and finish it at home?

PEP is a 28-day course, so ask for sufficient supply and written documentation before flying. It must be started within 72 hours of exposure and should not be deferred until you are home.

Should I buy antibiotics from a pharmacy instead of testing?

No. Partial or incorrect treatment can mask infection without clearing it, complicates later diagnosis and contributes to antibiotic resistance, which is a particular concern with gonorrhoea.

Can I get my results after I have left Thailand?

Yes. Results can be delivered securely and reviewed by teleconsultation, with treatment arranged accordingly.

When should I test after getting home?

Around two weeks for chlamydia and gonorrhoea if not already done, six weeks for HIV and syphilis, and twelve weeks for a definitive result. If you took PEP, the schedule restarts from the end of the course.

Do I need vaccinations as well?

Hepatitis A and B vaccination is worth checking if you are not already immune, and can be arranged alongside testing.

Sources and further reading

1. CDC Sexually Transmitted Infections Treatment Guidelines
2. WHO: HIV post-exposure prophylaxis guidance
3. MedEx PEP and PrEP services

Medical disclaimer: This article is general health information and does not replace medical advice, diagnosis or treatment. Laboratory reference ranges differ between laboratories and results must be interpreted alongside your symptoms, medicines and medical history. Speak with a qualified clinician before starting, stopping or changing any treatment. Service details, inclusions and prices can change — confirm them with MedEx before booking.