STI Test London: Where to Go, What It Costs and When to Get Tested
Looking for a private STI clinic in London? Worried about a recent sexual encounter? Or simply want to check your sexual health without unnecessary delays?
Discover how STI testing works, what the results mean and how to arrange discreet testing at Marylebone Diagnostic Centre.
You may feel completely healthy. You may have noticed a symptom. Or perhaps something happened recently and you simply want reassurance. Whatever brought you here, getting an STI test should be straightforward, confidential and free from judgement.
Where can I get a private STI test in London?
Marylebone Diagnostic Centre (MDC) provides private STI and STD testing at 73 Baker Street, Central London. The clinic offers walk-in sample collection during its published walk-in hours, as well as bookable appointments. No GP referral is required.
Testing options include HIV, syphilis, chlamydia, gonorrhoea and broader sexual health profiles. Same-day sample collection is available, while laboratory results usually follow within the turnaround stated for your selected test.
Explore MDC Sexual Health Testing →Choosing an STD test clinic in London: what actually matters?
When people search for “STD test London” or “private STI clinic London”, they are often looking for more than the nearest clinic.
They want clear answers, confidentiality, appropriate testing and a straightforward way to get their results.
Confidentiality
You should feel comfortable discussing your concerns without embarrassment. MDC provides private appointments and confidential testing.
The right test
Not every STI is detected by the same sample. Blood, urine and swabs may be needed depending on the infection and exposure.
Convenient access
MDC’s Baker Street clinic offers walk-in testing during published hours, with appointments available for patients who prefer to book.
Clear next steps
Understanding a positive result, a negative result or the need for repeat testing is as important as collecting the sample.
Ready to arrange testing? Visit MDC’s private sexual health testing page to compare available tests and book.
How much do STD tests cost in the UK?
NHS sexual health testing is free. Private STD test prices vary depending on the infection being checked, the number of tests, the sample required and the service included.
At Marylebone Diagnostic Centre, patients can choose individual tests or combined sexual health profiles.
| MDC testing option | Published price | What it covers |
|---|---|---|
| HIV 1 & 2 / p24 Antigen | £79 | Laboratory HIV screening |
| Chlamydia & Gonorrhoea PCR | £99 | Two common bacterial STIs, at the sampled site |
| Sexual Health Basic | £149 | HIV, syphilis, chlamydia and gonorrhoea |
| Sexual Health Plus | £199 | Multi-target urine/swab PCR panel; does not replace HIV blood testing |
| Advanced Sexual Health | £249 | Broader screening; confirm the exact panel and sample requirements |
Prices reflect MDC’s published listings reviewed for this article. Confirm current prices, included sample collection and any consultation or treatment charges before booking.
Is 2 weeks too early for an STD test?
This is one of the most important questions to ask before testing.
Two weeks after exposure is generally an appropriate time to test for chlamydia and gonorrhoea. However, it may be too early to reliably exclude HIV, syphilis or some other infections.
The period between exposure and when a test can reliably detect an infection is called the window period.
| Infection | Common testing window | What to know |
|---|---|---|
| Chlamydia | 2 weeks | Earlier testing may miss a recent infection. |
| Gonorrhoea | 2 weeks | Throat, rectal or genital sampling may be needed. |
| HIV | Around 45 days for a laboratory fourth-generation blood test | The window depends on the test method. |
| Syphilis | Up to 12 weeks for routine screening | Earlier assessment is needed if symptoms are present. |
These are general screening windows, not a substitute for individual advice. Testing after treatment, symptoms and the type of laboratory assay can change the recommended timing.
If you think you may have been exposed to HIV within the previous 72 hours, seek urgent advice about HIV post-exposure prophylaxis (PEP) from an NHS sexual health service or emergency department. Do not wait for a routine test.
Find the Right STI Test at MDC →What are the 7 warning signs of an STI?
There is no single set of symptoms that diagnoses an STI. However, seven common warning signs are worth recognising.
1. Unusual discharge
A change in discharge from the penis, vagina or anus can indicate an infection.
2. Burning when urinating
Pain or burning when passing urine can occur with chlamydia, gonorrhoea or other conditions.
3. Genital sores or blisters
Painful blisters or painless sores may require assessment for herpes, syphilis or other causes.
4. Genital itching
Persistent irritation around the genitals or anus deserves assessment. Not all itching is caused by an STI.
5. Pelvic or testicular pain
Lower abdominal discomfort, testicular pain or swelling may require prompt medical attention.
6. Unusual bleeding
Bleeding between periods or after sex may have several causes, including infection.
7. Rash, lumps or warts
New skin changes around the genitals or elsewhere may need examination and testing.
If you have severe pelvic pain, sudden testicular pain, fever with significant illness, or rapidly worsening symptoms, seek urgent medical assessment.
Explore Confidential STI Testing →How common is an STD from a BJ (oral sex)?
Oral sex, including giving or receiving a blowjob, can transmit certain STIs.
The exact risk depends on the infection, whether a partner has that infection, the type of contact, condom use and other factors. There is no reliable single percentage that applies to every oral-sex encounter.
Infections that may spread through oral sex
- Gonorrhoea
- Syphilis
- Herpes simplex
- Chlamydia, less commonly at the throat
- HPV
What about HIV?
HIV transmission through oral sex is much less likely than through unprotected anal or vaginal sex.
However, risk assessment should consider the full circumstances of the exposure.
Can a urine test detect an STI in the throat?
Not reliably. A urine sample checks the relevant genital or urinary site. It does not rule out an infection located in the throat.
If your concern involves oral sex, tell the clinic what happened. A throat swab may be appropriate, particularly for gonorrhoea.
You can explore available genital and site-specific tests through MDC’s sexual health services .
STI testing questions patients ask privately
Tap each flashcard for a quick, straightforward answer.
STD test London walk-in: can I visit without booking?
If you are searching for an “STD test London walk in”, you may not want to wait for an appointment.
Marylebone Diagnostic Centre welcomes walk-in sexual health testing during its published walk-in hours: Monday to Saturday, 8am–4pm.
Walk-in capacity and test availability can change, so calling before travelling is sensible, especially if you need a particular swab or a clinical assessment.
What happens when you arrive?
- Explain which infection or exposure concerns you.
- Confirm the appropriate test and sample site.
- Have your blood, urine or swab sample collected.
- Receive information about result timing and follow-up.
Same-day STI testing does not mean every result is available on the same day. Many laboratory tests take approximately 1–2 working days, depending on the test.
View Walk-In STI Testing Options →Where can I get a private gonorrhoea test in London?
Gonorrhoea is a bacterial STI that can affect the genitals, rectum or throat. Some people experience discharge or pain when urinating, while others have no symptoms.
Testing commonly uses a urine sample or swab, depending on the anatomical site.
At MDC, gonorrhoea testing is available through selected individual tests and sexual health profiles.
If you have had oral or anal sex, mention this before sample collection. A genital sample alone may not detect infection at another site.
STI test in North London: is MDC a convenient option?
If you live or work in Camden, Islington, Highgate, Hampstead, Finchley, Archway or another part of North London, you may be looking for a discreet clinic that is straightforward to reach.
MDC is based at 73 Baker Street, Marylebone, Central London, rather than operating a separate North London branch.
Baker Street station is served by several Underground lines, making the clinic accessible from many areas of London.
Patients can visit for private sexual health testing without a GP referral.
Which sexual health test should you choose?
Your test should reflect your symptoms, sexual history, sample sites and the time since your last exposure.
Sexual Health Basic
£149Tests for four commonly screened infections:
- HIV
- Syphilis
- Chlamydia
- Gonorrhoea
Uses blood and urine or swab samples as appropriate.
Explore Basic Screening →Sexual Health Plus
£199A broader urine/swab PCR panel that includes chlamydia, gonorrhoea and selected additional organisms.
It does not replace HIV and syphilis blood testing. Some organisms included in broad panels do not require routine screening without a clinical indication.
Explore Sexual Health Plus →Advanced Sexual Health
£249A broader testing option for patients whose history suggests additional screening may be appropriate.
Review the current panel and discuss suitability before choosing.
Explore Advanced Screening →All MDC Sexual Health Tests
Not sure whether you need a blood test, urine test, throat swab or combined profile?
Start with MDC’s main sexual health page to explore the available options.
View All STI Testing →Frequently asked questions about STI testing in London
How much does a private STD test cost in London?
At MDC, selected individual tests are listed from £79, while Sexual Health Basic is £149 and Sexual Health Plus is £199. NHS sexual health testing is available free of charge. Check MDC’s current price list before booking.
Is 2 weeks too early for an STD test?
Two weeks is generally suitable for routine chlamydia and gonorrhoea screening. HIV, syphilis and other infections can require a longer window. If you have symptoms, seek assessment without waiting.
What are the 7 warning signs of an STI?
Common signs include unusual discharge, burning when urinating, genital sores, itching, pelvic or testicular pain, unusual bleeding and rashes or warts. Many infections have no symptoms.
Can you catch an STD from a blowjob?
Yes. Oral sex can transmit gonorrhoea, syphilis, herpes and some other infections. Risk varies by infection and circumstances. A throat swab may be needed after oral exposure.
Can I get a same-day STI test in London?
MDC offers same-day sample collection during available walk-in hours and appointments. Most laboratory results are not instantaneous. Confirm the turnaround for your selected test.
Can I walk into an STD clinic without an appointment?
MDC’s published sexual health walk-in hours are Monday to Saturday, 8am–4pm. You can also book ahead. Call before travelling to confirm availability.
Where can I get an STI test near North London?
Marylebone Diagnostic Centre is at 73 Baker Street, Central London, accessible by public transport from many North London areas. It is not a North London branch.
Does a negative STI test mean I am definitely clear?
Not always. Testing too early, using the wrong sample site or testing for only some infections can leave an infection undetected. Ask whether repeat or additional testing is needed.
Do I need a throat swab after oral sex?
It depends on the exposure and infections being assessed. If the throat may have been exposed, a throat swab can be appropriate. A urine test alone does not rule out throat gonorrhoea.
What happens if my STI test is positive?
You should receive guidance about clinical follow-up, appropriate treatment, partner notification and any repeat testing. Ask MDC what follow-up is included with your test and what may require an additional appointment.
Visit Marylebone Diagnostic Centre for STI testing in London
Marylebone Diagnostic Centre
73 Baker Street, London W1U 6RD
Telephone: 020 7724 0540
Published sexual health walk-in hours: Monday–Saturday, 8am–4pm. Confirm before travelling.
Convenient for patients from Marylebone, Westminster, the Harley Street area, Central London and North London.
Your sexual health deserves clear answers, not uncertainty.
Whether you want a routine STI screen, need testing after a recent encounter, or are concerned about symptoms, Marylebone Diagnostic Centre offers a discreet way to take the next step.
Explore available tests, compare prices and arrange your visit to Baker Street.
Medical references and further reading
- NHS – Sexually transmitted infections
- NHS – Gonorrhoea
- Sexual Health London – STI testing window periods
- NHS Sexual Health Oxfordshire – When to test
This article provides general sexual health information and does not replace individual medical advice. Testing requirements depend on exposure, symptoms, infection and sample site. Prices, walk-in hours and turnaround times should be confirmed before attending.
