Chlamydia Testing UK: Home Test Kits, Clinics & What Happens Next
Key fact: Up to 70% of women and 50% of men with chlamydia have no symptoms. A urine sample or swab tested using NAAT (nucleic acid amplification test) is the only reliable method of detection — and can be done at home with a kit that is as accurate as a clinic test when used correctly.
99%+
Sensitivity of NAAT testing — the most accurate method available for chlamydia
2 weeks
Minimum window period before testing after possible exposure
3 months
Recommended retest interval after treatment to detect reinfection
Why Testing Matters
Chlamydia cannot be diagnosed by clinical examination alone. In most cases, infected individuals have no symptoms whatsoever — making symptom-based detection entirely unreliable. The only way to know whether you have chlamydia is to obtain a laboratory test result.
The case for routine testing is compelling. Untreated chlamydia can persist for months or years, silently damaging the reproductive tract. In women, the most serious consequences — pelvic inflammatory disease (PID), fallopian tube scarring, and infertility — can develop and progress in people who feel entirely well and have no idea they are infected. Early detection through testing and prompt treatment prevents these outcomes. See our full guide to chlamydia symptoms and complications.
Who Should Get Tested?
BASHH and the National Chlamydia Screening Programme (NCSP) recommend testing in the following circumstances:
- Sexually active people under 25 — annual testing is recommended, or after every new sexual partner. This age group accounts for the majority of diagnoses in the UK.
- Anyone with symptoms consistent with chlamydia: unusual discharge, pelvic pain, burning urination, bleeding between periods, or testicular discomfort.
- Anyone whose partner has been diagnosed with chlamydia, regardless of whether you have symptoms.
- Before intrauterine device (IUD) insertion or other gynaecological procedures, to reduce the risk of ascending infection.
- Women attending abortion services — BASHH recommends testing at the time of abortion referral.
- Anyone who has had unprotected sex with a new partner whose STI status is unknown.
- All pregnant women — chlamydia in pregnancy can cause neonatal infection. Testing is offered at booking in some areas of England.
- People over 25 who have had a change of sexual partner or multiple partners — the age cut-off for opportunistic screening does not mean testing is less important.
How Is Chlamydia Tested?
Chlamydia is diagnosed using a nucleic acid amplification test (NAAT) — a molecular technique that detects Chlamydia trachomatis DNA or RNA in the sample. NAAT is the gold-standard method with sensitivity above 99% and specificity above 99%. It has replaced older culture-based methods and non-amplified tests (which are no longer in routine clinical use) due to its superior accuracy.
| Sample type | Who it’s for | How collected |
|---|---|---|
| First-void urine (FVU) | Men (primary sample); also used in women when vaginal swab not possible | First 20–50 ml of urine stream into a sterile container. Do not urinate for 1 hour beforehand. |
| Self-taken low vaginal swab (LVS) | Women — primary sample for home kits; as accurate as clinician-taken cervical swab | Swab inserted 2–3 cm into vagina, rotated for 15–30 seconds. No speculum required. |
| Clinician-taken cervical swab | Women attending clinic | Taken during speculum examination. No more accurate than self-taken LVS per BASHH evidence. |
| Rectal swab | Anyone who has receptive anal sex | Self-taken or clinician-taken swab from the rectum. Strongly recommended for MSM. |
| Pharyngeal (throat) swab | Anyone who has given oral sex to a partner with possible chlamydia | Clinician-taken swab from the posterior pharynx. Less commonly tested; discuss with clinician. |
For MSM (men who have sex with men): BASHH recommends comprehensive 3-site testing — urine, rectal swab, and pharyngeal swab — at least annually and ideally every 3 months in those with multiple partners. Urethral-only testing misses extra-genital infection, which is common and typically asymptomatic.
Home Test Kits vs Sexual Health Clinic
Both home test kits and clinic-based testing use NAAT methodology and offer the same analytical accuracy. The difference is in accessibility, speed, and privacy.
Home test kit
Self-collected urine or swab sample sent to an accredited laboratory. Results typically in 2–5 working days. Private, discreet, and clinically equivalent to clinic testing. Available free via some local authorities or purchased privately online. Suitable for most straightforward situations in adults.
Sexual health clinic
Full STI screen including chlamydia, gonorrhoea, syphilis, and HIV. Same-day results sometimes available. Recommended for: MSM requiring 3-site testing, symptomatic patients, those who may have been exposed to multiple STIs, or anyone who needs immediate clinical assessment and treatment.
Home kits do not test for gonorrhoea unless specified. Many home chlamydia kits test only for Chlamydia trachomatis. If you need a combined chlamydia and gonorrhoea test — which is advisable after high-risk exposure — ensure your kit specifies both, or attend a sexual health clinic for a comprehensive screen.
How to Collect Your Sample Correctly
Incorrect sample collection is the most common cause of false-negative home test results. Follow these steps carefully.
For women — self-taken vaginal swab
1
Wash hands thoroughly
Use soap and water for at least 20 seconds before handling the swab. Do not touch the tip of the swab at any point.
2
Insert the swab into the vagina
Insert the swab 2–3 cm into the vaginal opening (not just the labia). Rotate gently for 15–30 seconds to collect cells from the vaginal walls.
3
Place in the transport tube immediately
Insert the swab into the transport medium provided and break off at the marked point. Seal the tube. Label with your name and date of birth exactly as specified in the kit instructions.
4
Return on the same day if possible
Post or drop off your sample as quickly as possible. Most kits specify a maximum storage time at room temperature. Check and follow the kit’s specific instructions.
For men — first-void urine (FVU)
- Do not urinate for at least 1 hour before collecting your sample. Urinating beforehand washes chlamydial organisms out of the urethra and can cause a false-negative result.
- Collect the first 20–50 ml of the urine stream — the very start of urination — into the container provided. Do not fill the container with mid-stream urine.
- Seal, label, and return as directed. Do not refrigerate unless specifically instructed.
Window Period: When to Test After Exposure
NAAT tests detect chlamydial DNA, which must be present at sufficient concentration in the sample to trigger a positive result. If you test too soon after exposure — before the infection has established — you may receive a false-negative result.
Tested Positive? Get Treatment Without Visiting a Clinic
Access Doctor offers discreet online consultations. Upload your positive test result and our pharmacist independent prescribers will assess your case and issue a prescription for doxycycline or azithromycin. Same-day dispatch, next-day delivery. GPhC pharmacy #9011198.
Start Treatment Consultation →What a Positive Result Means
A positive NAAT result for chlamydia confirms active infection with Chlamydia trachomatis. False positives with NAAT are extremely rare in accredited laboratories. A positive result means you need antibiotic treatment and that recent sexual partners need to be notified and offered testing.
A positive result does not tell you how long you have had the infection — chlamydia can persist asymptomatically for months or years. It also does not indicate infidelity; the infection may have been present before your current relationship.
Steps after a positive result
- Start antibiotic treatment promptly. See your GP, sexual health clinic, or use an online prescribing service. Current first-line treatment is doxycycline 100 mg twice daily for 7 days. See our doxycycline guide.
- Abstain from sex until you and any partners have completed treatment and observed the required abstinence period (7 days after single-dose azithromycin or 7 days after the last doxycycline tablet).
- Notify recent partners. All partners from the past 6 months should be informed and offered testing. See below for guidance on partner notification.
- Consider a full STI screen. Chlamydia may co-exist with other STIs including gonorrhoea. If you have not had a comprehensive STI screen recently, attend a sexual health clinic or arrange one online.
- Retest at 3 months to detect reinfection — not to confirm the first infection has cleared.
What a Negative Result Means
A negative NAAT result indicates that Chlamydia trachomatis DNA was not detected in your sample at the time of testing. In the vast majority of cases this means you do not have chlamydia. However, a negative result should be interpreted in context:
- If you tested within 2 weeks of exposure, the result may be a false negative due to the window period. Retest at 6 weeks.
- If the sample was collected incorrectly (e.g. urinating before collecting urine), a false negative is possible.
- A negative result only covers the site tested. If you have had anal or oral sex and only a urine sample was tested, rectal or pharyngeal infection may still be present.
Retesting After Treatment
BASHH recommends the following retesting schedule after treatment:
- 3 months post-treatment — retest for chlamydia (and gonorrhoea if relevant). This is to detect reinfection, not to confirm the original infection cleared.
- Test of cure — not routinely recommended for non-pregnant patients who completed a full course of doxycycline or azithromycin for urogenital chlamydia. It is recommended in pregnancy (at 5–6 weeks post-treatment), for rectal or pharyngeal infection, and if symptoms persist.
Partner Notification
Partner notification — informing recent sexual partners that they may have been exposed to chlamydia — is an essential part of infection control. Chlamydia has no visible signs in most people; partners cannot know they are infected without being told and tested. Untreated partners are the primary source of reinfection.
The standard lookback period recommended by BASHH is the past 6 months, or to your most recent sexual contact if sooner. All partners within this window should be informed, regardless of whether you had symptoms or how long ago the contact occurred.
You can notify partners yourself, or ask your local sexual health clinic to do so on your behalf without identifying you (anonymous notification). Some clinics offer “contact slips” — anonymous notification cards that partners can use to attend a clinic. See our full partner notification guide for practical advice on how to approach this conversation.
First-line treatment (BASHH 2025)
Doxycycline 100 mg
100 mg twice daily for 7 days. Start treatment after a confirmed positive result. Prescription following clinical assessment.
View doxycycline →Second-line treatment
Azithromycin 1 g
Single-dose alternative. For use when doxycycline is contraindicated. Prescription following clinical assessment.
View azithromycin →Frequently Asked Questions about Chlamydia Testing
Are home chlamydia test kits as accurate as clinic tests?
Yes. Both home kits and clinic tests use NAAT methodology and send samples to the same type of accredited laboratory. Clinical studies have confirmed that self-collected vaginal swabs and first-void urine samples — the standard samples for home kits — perform equivalently to clinician-collected samples. Accuracy of the result depends on correct sample collection, not on where testing is initiated.
How long do chlamydia test results take?
Home kit results typically take 2–5 working days from the date the laboratory receives your sample. Some online services offer accelerated turnaround. Sexual health clinics may offer same-day or next-day results; some offer point-of-care NAAT testing with results within 60–90 minutes, though this is not universally available.
Can I get a free chlamydia test in the UK?
Yes. Free testing is available from: NHS sexual health clinics (GUM clinics); some GP surgeries; pharmacies participating in local authority sexual health programmes; and online via NHS-commissioned postal testing services available to under-25s in many areas of England. Search “free chlamydia test” with your postcode on the NHS or local authority website to find services in your area.
Should I test for chlamydia even if I feel fine?
Yes — particularly if you are under 25 and sexually active, or if you have had a new partner in the past year. Most people with chlamydia feel completely well. The absence of symptoms is not a reliable indicator of infection status. Annual testing is the BASHH and NHS recommendation for sexually active people under 25.
Can a urine infection test detect chlamydia?
No. Standard urine dipstick testing (used to diagnose urinary tract infections by detecting nitrites, leucocytes, and blood) does not detect chlamydia. A NAAT test on a first-void urine sample is required. This is a separate test entirely and must be specifically requested. Many patients with chlamydial urethritis or cervicitis are initially and incorrectly treated for UTI because their symptoms overlap and the wrong test is performed.
Is chlamydia testing confidential?
Yes. Sexual health clinic records are separate from GP records and are not shared without your consent. Home testing services are similarly confidential. If you attend an NHS sexual health clinic and test positive, staff will discuss partner notification with you — but this process is voluntary and does not result in partners being contacted without your involvement unless you choose clinic-assisted notification.
Do I need to test for other STIs at the same time?
It is good practice. Chlamydia and gonorrhoea frequently co-exist, and both are typically asymptomatic. If you are testing for chlamydia after unprotected sex or a new partner, a comprehensive screen including gonorrhoea, syphilis, and HIV is advisable. Many home kits now offer combined chlamydia and gonorrhoea testing. Full STI screens are available free at NHS sexual health clinics.
References
- BASHH. UK National Guideline for the Management of Infection with Chlamydia trachomatis. 2025 update. Available at: www.bashh.org/guidelines
- NICE. Chlamydia — uncomplicated genital: Clinical Knowledge Summary. 2025. Available at: cks.nice.org.uk
- Public Health England. National Chlamydia Screening Programme: Standards. 2014. Available at: gov.uk/government/publications/ncsp-standards
- NHS. Chlamydia: Diagnosis. 2023. Available at: www.nhs.uk/conditions/chlamydia/diagnosis/
- Chernesky MA, Hook EW 3rd, Martin DH, et al. Women find it easy and prefer to collect their own vaginal swabs to diagnose Chlamydia trachomatis or Neisseria gonorrhoeae infections. Sex Transm Dis. 2005;32(12):729–733.
- UKHSA. Sexually transmitted infections and gonorrhoea: annual data tables. 2024. Available at: gov.uk/government/statistics
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. If you have received a positive chlamydia test result, please seek clinical advice for appropriate treatment. Always consult a qualified healthcare professional about your individual circumstances. In a medical emergency, call 999.