The waiting room at a big city sexual health clinic on a Monday morning is one of the great levellers of British life. A lad in a hi-vis jacket on his way to a shift. Two students pretending not to know each other. A woman in a good suit answering emails. A man in his sixties doing the crossword. Nobody looks at anybody, and nobody cares, and after twenty minutes a nurse calls a first name, or a number, and the whole thing turns out to be about as dramatic as getting your car through its MOT.
I avoided those rooms for years. I assumed a test meant a morning off work, a queue of people I knew, and a clinician peering over her glasses at my life choices. None of it was true. If you have casual sex in the UK, you are sitting on one of the best free sexual health systems in the world, and there is a decent chance you barely use it. This guide, written for the people who meet partners through hookup sites like Kommons, through apps, in bars or anywhere else, is the practical version of what you need to know.
There is no moralising here. Sex is fine. Casual sex is fine. Untreated infections are not, mainly because so many of them are silent, easy to treat and quietly damaging if left alone. I'm not a clinician, and nothing below replaces advice from one. Where I say "ask the clinic", I mean exactly that, and the clinic will be glad you did.
A free, confidential service with roots in the trenches
The backbone of all this is the NHS sexual health clinic, still often called a GUM clinic, short for genitourinary medicine. The system is older than the NHS itself. During the First World War, alarm about venereal disease among troops and civilians led to a Royal Commission and then, in 1916, to regulations setting up free and confidential treatment centres across the country. The founding logic was public health rather than kindness: if people fear exposure or a bill, they don't come, and if they don't come, infections spread. That logic still shapes how clinics work more than a century later.
In practice it means this. Clinics are free. They are confidential. You don't need a GP referral, and your GP won't be told unless you ask them to share results. Many clinics are happy with a first name only, and STI testing and treatment are available to anyone regardless of immigration status. That last point matters more than people realise, particularly for those who have been told, wrongly, that they need to show papers to be seen.
Finding one is straightforward. In England, the NHS sexual health service finder will show you what is near your postcode. In Scotland, NHS inform lists services by health board, and in Glasgow the Sandyford is the name everyone knows, as the Chalmers Centre is in Edinburgh. In Wales, the Sexual Health Wales online testing service sits alongside the clinics. Northern Ireland's clinics are run by the health and social care trusts. London has the heavy hitters, with 56 Dean Street in Soho and the Mortimer Market Centre near Warren Street, while further north The Northern in Manchester and the New Croft Centre in Newcastle serve huge catchments. Our regional guides cover the social side, from the London hookup scene to the northern England hookup guide, but the clinic list is the more useful bookmark.
Most clinics now run a mix of booked appointments and walk-in sessions. In the bigger cities, walk-ins can mean a long wait and occasionally being turned away once capacity is reached, so arrive before opening with a book and a charged phone. Booked slots are usually faster. If you have symptoms, say so when you call, because you are more likely to be seen promptly.
The appointment itself is less of an ordeal than the anticipation. There's a short conversation about recent partners and the kind of sex you've been having, and yes, they have heard everything, several times, that week. Then usually a urine sample or a swab you take yourself in a cubicle, and a blood test for HIV and syphilis. Results tend to arrive by text within days. If you need treatment, it is free, and if you would rather not ring a former partner yourself, the clinic can notify them anonymously. That service is underused, and it is a quiet kindness to people you may never see again.
A testing kit on the kitchen table
If a clinic visit is a faff, there is a good chance you don't need one. Many English councils offer free home STI test kits by post, with SH:24 running the service in a lot of areas and other providers elsewhere. Whether you are eligible depends on your postcode, so put it into the NHS finder or your council's sexual health page and see what appears. In Wales, the Sexual Health Wales service does the same job nationally.
The process is unglamorous and efficient. You order online and the kit arrives in plain packaging that gives nothing away to housemates or the bloke at the sorting office. You do a swab or urine sample and a finger-prick blood test at the kitchen table, post it back in the prepaid envelope, and get results by text. If anything comes back positive, you are directed to a clinic for treatment.
The finger-prick is the bit everyone botches the first time. Have a hot shower beforehand, drink a glass of water, keep your hand below your heart and let gravity do the work. Massage the finger from the base rather than squeezing the tip. If you fill the little tube to the line without fainting or redecorating the bathroom, you have done better than most.
How often to test is the question I get asked most, and there is no single answer that fits everyone, so ask a clinic about your own circumstances. As a rule of thumb that most clinicians would recognise, test at least once a year if you are having sex with new partners, more often if you have several, with every three months a common suggestion for people who are busy, and always after a specific risk or the moment you notice symptoms. Chlamydia is the classic reason routine testing matters: it frequently causes no symptoms at all, and left untreated it can affect fertility. Gonorrhoea and syphilis can also be quiet. A clear conscience is not a clear result.
And if a result does come back positive, it is worth knowing how undramatic that usually is. The common bacterial infections are treated with antibiotics, often a short course or a single dose, and the clinic will tell you how long to avoid sex afterwards and whether you need a test of cure. Herpes and HIV are managed rather than cured, and modern HIV treatment means people on effective medication can live long lives and, once the virus is undetectable, cannot pass it on through sex. Nobody at the clinic will treat a diagnosis as a verdict on your character. It is a clinical fact with a clinical response, and the earlier it is found, the simpler that response tends to be.
Why the morning-after test tells you almost nothing
Here is the trap that catches anxious people. You have a night that worries you, you lie awake, and at nine the next morning you are in the clinic queue or ordering a kit. It feels responsible. It isn't useless, because it may pick up something you already had, but it can't tell you anything about the night you are worried about.
Every test has a window period, the time between exposure and the point at which an infection reliably shows up. For chlamydia and gonorrhoea, it is roughly two weeks. For HIV, a fourth-generation test is considered reliable at 45 days. Syphilis has its own timetable. Test inside those windows and a negative result is, at best, provisional. The clinic will tell you when to come back, and that second test is the one that counts.
The exception is HIV risk that is recent and serious, where waiting is the wrong move entirely. That is what PEP is for, and it has a hard deadline, so if that's why you are reading this, skip straight to the section about the seventy-two hours below and then come back.
The window period also changes how you should think about a partner's "I'm clean, I got tested last month". It may be entirely honest. It only covers what they had up to a couple of weeks before that test, and nothing since. It's useful information, not a guarantee, and nobody should take it as a reason to skip a condom they would otherwise have used.
Condoms, and the conversation that is easier by text
Condoms are unfashionable in a world of pills and injections, and they remain the cheapest, simplest protection against most STIs and the only thing on this page that also prevents pregnancy. Many clinics will hand them over free, and in several areas there are free condom schemes for under-25s. Otherwise, supermarket own-brand packs work perfectly well and cost a few quid. Paying more buys you branding, not safety, provided the box carries the UKCA or CE mark.
Most failures are user error rather than manufacturing faults. Fit matters: a condom that is too tight is more likely to split, and one that is too loose is more likely to slip off, and the "one size" myth has caused a lot of unnecessary breakages. Use water-based or silicone-based lube, never oil-based products with latex, because oil degrades it quickly. Check the date. Don't keep one in your wallet for six months, where body heat and friction slowly cook it. Pinch the tip, roll it on the right way round, and put it on before any genital contact rather than halfway through, which is when most of the risk has already happened.
The conversation is the harder part, and my firm view is that it belongs in the messages before you meet rather than in the heat of the moment. Typing "just so you know, condoms are a must for me" at seven in the evening is effortless. Saying it at midnight with your jeans round your ankles is not. Anyone who sulks or argues when you raise it has told you something useful about how the rest of the night would go. In paid encounters the provider sets those terms and you respect them; our guide to escort etiquette in the UK covers that properly.
One thing here is not etiquette at all. Removing a condom during sex without the other person's agreement, sometimes called stealthing, can be rape in England and Wales, and the courts have treated deception about condom use as capable of undermining consent. Agreement to sex with a condom is not agreement to sex without one. The legal side is explained in consent and UK law for hookups, and it is worth reading even if you think you already know it.
PrEP, the pill that changed the arithmetic of HIV
PrEP, short for pre-exposure prophylaxis, is medication taken before sex that is highly effective at preventing HIV when used as prescribed. It is free on the NHS across the UK through sexual health clinics. Scotland and Wales made it available in 2017, Northern Ireland in 2018, and England, after years of trials and a public argument about who should pay, made it routinely available in October 2020. The fight over funding in England is a story in itself, and the short version is that the clinicians and campaigners who insisted it was worth it turned out to be right.
It is best known among gay and bisexual men, but it isn't reserved for them. Anyone at higher risk of HIV can ask about it, including straight men and women with partners from places where HIV is more common, people whose partners are living with HIV and aren't on effective treatment, and people who sell sex. The clinic will talk through whether it suits you, whether daily or event-based dosing makes sense, and what monitoring you need. That usually includes regular HIV tests and kidney function checks, which is less of a chore than it sounds and has the side benefit of keeping you on a testing routine.
What PrEP doesn't do is protect against other STIs or pregnancy. It is one layer of protection, not the whole wardrobe. Clinicians sometimes worry, with some justification, that people treat it as permission to drop condoms altogether. Use it for what it is good at.
Getting an appointment can take a while in some areas because demand outstrips capacity. Ask anyway. Ask again if you hear nothing. Clinics would far rather deal with persistent patients than diagnose avoidable infections. While you are there, it's also worth asking about vaccines: the mpox vaccine has been offered through clinics to eligible groups, and some clinics offer hepatitis and HPV vaccination to people who qualify.
Seventy-two hours: what to do after a real HIV risk
PEP, post-exposure prophylaxis, is the emergency brake. If you think you have been exposed to HIV, through a condom that burst, sex without one with someone whose status you don't know, or an assault, PEP can reduce the chance of infection taking hold. It has to be started as soon as possible, ideally within 24 hours, and no later than 72. Every hour matters, so this is the one part of sexual health where the instinct to rush is correct.
If a sexual health clinic is open, go there. Out of hours, go to A&E and say clearly and early that you need to be assessed for PEP after a possible HIV exposure. Use those words. Busy triage nurses respond to specific requests far better than vague worry. You may have to wait, and you may be asked detailed questions about the encounter. Answer them honestly; they determine whether PEP is recommended. What you should not accept is "come back on Monday" if Monday takes you beyond the window. Say Sunday night in Leeds, after a Saturday encounter: you are still comfortably inside the deadline, and the A&E at the LGI is the place to go rather than waiting for a clinic to open.
PEP is a course of tablets taken for several weeks, and you'll need follow-up testing afterwards. Some people get side effects, usually manageable, and the clinic will tell you what to watch for. It is a safety net for when something goes wrong, not a plan.
If the risk came from sex you did not agree to, you can get medical care without having to involve the police unless and until you choose to. Sexual assault referral centres operate across the UK and can provide PEP, emergency contraception, support and the option of storing forensic evidence while you decide what to do. A&E, a clinic or NHS 111 can point you to the nearest one.
The split condom and the second question
For anyone having sex that could lead to pregnancy, a split condom raises a second question alongside infection, and the clock on this one runs too. Emergency contraception is free from many pharmacies in England, as well as from GPs and sexual health clinics, and arrangements are available elsewhere in the UK through pharmacies and clinics too. The pills work better the sooner they are taken, and how long you have depends on which one. The copper coil, fitted by a clinic, is the most effective form of emergency contraception and has a longer window, so if that's something to consider, ring the clinic first thing.
Men, this is partly yours to manage. If the condom split, say so straight away, not the next morning and not never. Offer to go to the pharmacy together or to cover any cost, stay reachable, and don't disappear back into the app as though it didn't happen. A thoroughly awkward two-minute conversation costs you nothing compared with what silence can cost the other person. It is also, in my experience, the moment people decide whether you were a decent hookup or a story they tell their friends with a grimace.
Making it a habit rather than a panic
The people I know who handle all this well rarely think about it. They test on a schedule rather than in a fit of anxiety. They keep condoms in date and within reach. They know where their nearest clinic is, they've done a home kit once so it holds no mystery, and they have the conversation early, by text, before anyone is in a position to be embarrassed. It becomes as routine as the dentist, and is frankly less unpleasant.
Privacy is the other half of the habit. A message reading "your results are ready" on a lock screen can cause real trouble in a shared flat or a relationship, so turn off message previews if that worries you, and use an email address you control. Clinics are careful about what their messages say, but your phone is not. There is more along those lines in our guide to keeping hookups private and discreet, and the wider UK dating safety guide covers the meeting-up side of being careful.
None of this is a reason to have less fun. If anything it is the opposite: the person who knows they tested clean last month, who has condoms in the drawer and a clinic bookmarked, is the person who can relax. When you are ready to meet someone, you can browse Kommons, the free UK hookup site, by region, from Scotland to Wales and Northern Ireland. Free to join and free to message, which happens to be the same deal the NHS has offered on clinics since 1916.
Think back to that Monday waiting room, with the hi-vis jacket, the good suit and the crossword. Every one of those people had decided that twenty minutes of mild awkwardness was a fair price for knowing. They were right. Book the test. It takes less time than reading this did, and Kommons will still be there when you are done.