How Often Should You Get Tested? An STI Screening Schedule for Thailand

Sexual health testing guide · 2026

There is no universal testing interval. There is a sensible interval for your situation, and it is usually more often than people assume and less often than anxiety suggests.

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

Quick answer

Screening frequency should follow your circumstances, not a fixed rule. A reasonable baseline: test after each new partner, and at least annually if you are sexually active outside a mutually exclusive relationship where both partners have tested. More frequent screening — commonly every 3 to 6 months — is advised for people with multiple partners, men who have sex with men, people taking PrEP, and anyone with a recent STI, since reinfection is common. A routine screen usually covers chlamydia and gonorrhoea from all relevant sites, HIV and syphilis, with hepatitis testing and vaccination status reviewed.

In this guide

1. Working out your interval
2. What a routine screen should include
3. Prevention alongside testing
4. Making it routine rather than reactive

Working out your interval

These are starting points rather than rules. A clinician can tailor the interval — a short consultation is enough to set a plan.

What a routine screen should include

• Chlamydia and gonorrhoea PCR from all sites relevant to your exposures — urine or vaginal swab, plus rectal and pharyngeal where applicable. Site selection is the most commonly missed element.
• HIV — a fourth-generation laboratory test.
• Syphilis serology — treponemal and non-treponemal.
• Hepatitis B and C, depending on risk factors, vaccination status and previous testing.
• Cervical screening where eligible, which is a separate pathway from STI testing but often due around the same time.

What a routine screen should generally not include: Mycoplasma genitalium and Ureaplasma screening in asymptomatic people, and routine HSV serology. These generate results that are hard to act on and frequently lead to unnecessary antibiotics — explained in the STI PCR panel guide.

Prevention alongside testing

Testing detects; it does not prevent. The measures that reduce risk are worth reviewing at the same appointment:

• Condoms, which substantially reduce transmission of most STIs, though less so for those spread by skin contact such as herpes and HPV.
• HPV vaccination, which prevents the infections responsible for most cervical and several other cancers, and is effective for eligible adults as well as adolescents.
• Hepatitis A and B vaccination, both relevant to sexual transmission and straightforward to arrange — see MedEx vaccination services.
• PrEP for people with ongoing HIV risk, which is highly effective when taken as prescribed.
• PEP within 72 hours of a higher-risk exposure.
• Treating partners when you test positive, which is what prevents the next infection being your own.

Making it routine rather than reactive

The most common pattern is testing only after a scare, which means testing at the wrong time, under stress, and often too early to be informative.

A few things make it easier to keep regular:

1. Attach it to something else. Bundle sexual health screening into an annual health checkup so it is one appointment rather than a separate decision.
2. Use at-home collection. Self-collected kits and nurse-at-home draws remove the main practical barrier.
3. Set the reminder at the time of the test, particularly the three-month retest after any positive result.
4. Keep a record of what was tested, when, and from which sites. It saves duplicate testing and makes gaps visible.
5. Ask about sites explicitly. If nobody asks about oral or anal exposure, say so anyway — it changes which swabs are taken.

For timing after a specific exposure, see the window periods guide.

Frequently asked questions

How often should I get tested for STIs?

After each new partner, and at least annually if you are sexually active outside a mutually exclusive relationship where both partners have tested. Every 3 to 6 months is commonly advised for people with multiple partners, men who have sex with men, and people taking PrEP.

What should a routine STI screen include?

Chlamydia and gonorrhoea PCR from all relevant sites, a fourth-generation HIV test and syphilis serology, with hepatitis B and C depending on risk and vaccination status.

Should a routine screen include Mycoplasma genitalium or Ureaplasma?

Generally not in asymptomatic people. Guidelines advise against screening for these, since results are hard to act on and frequently lead to unnecessary antibiotics.

Do I need testing if I am in a monogamous relationship?

Routine screening is not usually needed once both partners have tested after the relevant windows and circumstances remain unchanged. Testing again makes sense if that changes.

How soon after treatment should I be retested?

Around three months, to check for reinfection rather than to confirm cure. Reinfection rates are high, most often from an untreated partner.

Does condom use mean I do not need testing?

Condoms substantially reduce transmission of most STIs but less so for infections spread by skin contact, such as herpes and HPV, and use is rarely perfect. Regular screening is still worthwhile.

Sources and further reading

1. CDC Sexually Transmitted Infections Treatment Guidelines: Screening Recommendations
2. BASHH UK national guidelines
3. MedEx STD and STI testing service
4. MedEx health checkup packages

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.