A possible HIV exposure is frightening. The most useful thing you can do in the first hours is act on clear information, not anxiety. This post covers exactly what PEP is, how it works, who it is suitable for and how to access it quickly in London, through both the NHS and privately at The Wright Practice.
PEP stands for post-exposure prophylaxis. It is a short course of antiretroviral medication, taken for 28 days, that can prevent HIV from establishing itself in the body after a possible exposure.
The word prophylaxis means prevention. PEP does not treat existing HIV infection. It works by blocking the virus during the very early stage, before it has had the chance to replicate and spread through the body’s cells. That is why timing matters so much.
PEP is not a vaccine and it is not a guarantee. Research suggests it reduces the risk of HIV transmission by at least 80% when started promptly, and possibly more when started within the first 24 hours. The earlier it begins, the more effective it is likely to be.
PEP is considered when there has been a realistic risk of HIV transmission and fewer than 72 hours have passed. Common situations where it may be appropriate include:
Not every possible exposure requires PEP. The level of risk depends on the type of exposure, the HIV status of the other person (if known) and whether the source has an undetectable viral load. Dr Dan Wright will assess your individual situation at a consultation and discuss whether PEP is clinically appropriate.
The 72-hour window is a hard limit: PEP is not prescribed beyond this point because evidence does not support its use. Within that window, earlier is better. Studies indicate the greatest effectiveness when treatment starts within 24 hours. Every hour matters.
24 hours: optimal window for starting PEP
After 72 hours: PEP is no longer an option. Book an HIV test at 28 days and again at 12 weeks.
PEP is a combination of two or three antiretroviral drugs taken daily for 28 days. Side effects can include nausea, fatigue and headache, particularly in the first week. They are usually manageable and tend to ease as the body adjusts. It is important to complete the full 28-day course even if you feel well, as stopping early reduces the medication’s effectiveness.
Completing PEP does not mean the episode is over. Follow-up testing is required:
Both routes are available in London. Understanding the difference helps you make the right decision for your situation.
| NHS (A&E) | The Wright Practice (private) | |
|---|---|---|
Access hours | 24/7 at A&E only | Same-day appointments, Mon-Fri |
Wait time | Variable, can be several hours | Typically seen within hours of calling |
Consultation | Triage environment | Unhurried, confidential with Dr Dan |
Cost | Free | Private fee applies (contact for current pricing) |
Follow-up | Referred to HIV clinic | 4-week and 12-week follow-up included |
Recommendation | If out of hours, go to A&E. Do not wait. | Preferred during clinic hours for a thorough assessment |
Dr Dan Wright will take a full clinical history, including the nature and timing of the exposure, your current health and any medications you are taking. The consultation is completely confidential.
If PEP is appropriate, a prescription will be provided on the same day with clear guidance on how to take the medication and what to expect in terms of side effects. If PEP is not appropriate, Dr Dan will arrange an HIV test at the right interval and discuss what happens next.
PEP is time-critical. If it has been fewer than 72 hours since a possible HIV exposure, contact The Wright Practice today for an urgent consultation with Dr Dan Wright at our Harley Street clinic.
Yes. The Wright Practice offers same-day PEP assessments during clinic hours. Dr Dan Wright can assess your situation and, where clinically appropriate, prescribe PEP on the day. If it is outside clinic hours, go directly to your nearest A&E, which can also provide PEP around the clock.
Yes. All consultations at The Wright Practice are completely confidential. We do not share information with your employer, your NHS GP (unless you ask us to), or any third party without your consent.
PEP is highly effective when started promptly, but it is not 100% guaranteed. Research suggests it reduces transmission risk by at least 80%. Completing the full 28-day course is essential: stopping early significantly reduces its protective effect. Follow-up HIV testing at 4 weeks and 12 weeks is required to confirm the outcome.
If the 72-hour window has passed, PEP is no longer an option. The next step is an HIV test at 28 days after exposure using the fourth-generation HIV duo test, which detects both the virus itself and antibodies. A final confirmatory test is usually done at 12 weeks. Dr Dan Wright can arrange both and guide you through what to do next.
PrEP (pre-exposure prophylaxis) is a daily medication that significantly reduces the risk of HIV acquisition before potential exposure, rather than after. If you are at ongoing risk, PrEP may be a more appropriate long-term strategy. Dr Dan can discuss both options at a consultation. PrEP and PEP are different medications, used at different points, and are not interchangeable.
Rated ★ ★ ★ ★ ★ from 192 Reviews
