&lt;h2&gt;&lt;strong&gt;HIV PEP: Emergency Post-Exposure Prophylaxis and Current Regimens&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;If you&#39;ve had a recent possible exposure to HIV&amp;mdash;through sex that may present a substantial risk of HIV transmission, a shared needle, sexual assault, or an occupational exposure such as a needlestick&amp;mdash;time matters. This guide explains what PEP is, how it works, and what current recommended regimens may involve.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;What Is PEP?&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;&lt;a href=&quot;https://www.cdc.gov/hiv/prevention/pep.html&quot;&gt;&lt;strong&gt;PEP&lt;/strong&gt;&lt;/a&gt; stands for post-exposure prophylaxis. It is a short course of HIV medication taken after a possible exposure to prevent HIV from establishing infection.&lt;/p&gt;
&lt;p&gt;PEP is considered emergency HIV prevention. It is not intended to replace ongoing prevention methods such as &lt;a href=&quot;https://hivinfo.nih.gov/understanding-hiv/fact-sheets/post-exposure-prophylaxis-pep&quot;&gt;&lt;strong&gt;PrEP&lt;/strong&gt;&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;The 72-Hour Window&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;PEP should be started &lt;strong&gt;as soon as possible and no later than 72 hours (3 days) after a potential HIV exposure&lt;/strong&gt;. The sooner it is started, the better. Ideally, PEP should begin within the first 24 hours when indicated.&lt;/p&gt;
&lt;p&gt;After 72 hours, PEP is generally not recommended because it is unlikely to be effective.&lt;/p&gt;
&lt;p&gt;If you think you may have been exposed to HIV, do not wait for symptoms to appear. Seek medical care immediately at an emergency department, sexual health clinic, urgent care centre, or other service that provides PEP.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;How Does PEP Work?&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;PEP uses a combination of antiretroviral medicines to prevent HIV from establishing infection after a potential exposure.&lt;/p&gt;
&lt;p&gt;It is taken as a &lt;strong&gt;full 28-day course&lt;/strong&gt;. PEP is not a single-dose treatment, and completing the full 28-day course as prescribed is essential for effectiveness.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Current PEP Regimens&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;PEP recommendations have evolved as newer HIV medicines have become available.&lt;/p&gt;
&lt;p&gt;In the United States, the updated guidelines from the &lt;a href=&quot;https://www.cdc.gov/mmwr/volumes/74/rr/rr7401a1.htm&quot;&gt;&lt;strong&gt;U.S. Centers for Disease Control and Prevention (CDC)&lt;/strong&gt;&lt;/a&gt; list the following as preferred non-occupational PEP (nPEP) options for adults and adolescents without contraindications:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;Bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF; Biktarvy)&lt;/strong&gt; &amp;mdash; one tablet once daily&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Dolutegravir (DTG) plus tenofovir alafenamide (TAF) or tenofovir disoproxil fumarate (TDF), plus emtricitabine (FTC) or lamivudine (3TC)&lt;/strong&gt;&amp;mdash;generally&amp;nbsp;taken once daily, depending on the specific medicines prescribed&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Other regimens may be used when a preferred option is not appropriate or available. Raltegravir-based regimens are no longer listed as preferred options in the 2025 CDC guidance because of their higher pill burden, but they may still be used in certain circumstances.&lt;/p&gt;
&lt;p&gt;The most appropriate regimen depends on factors such as kidney function, pregnancy status, other medicines, possible drug interactions, the type of exposure, and local clinical guidance. PEP should be prescribed by a qualified healthcare professional rather than selected or started without medical assessment.&lt;/p&gt;
&lt;p&gt;Important: In the United States, there are no medications specifically FDA-approved for non-occupational PEP (nPEP). The antiretroviral medicines recommended in the 2025 CDC nPEP guidelines are therefore used off-label for this purpose.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&amp;nbsp;&lt;/strong&gt;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Who Should Consider PEP?&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;According to current clinical guidelines (such as the 2025 U.S. CDC guidelines and UK BHIVA/BASHH standards), PEP may be appropriate after a single identifiable exposure that presents a substantial risk of HIV transmission, including:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Sexual assault&lt;/li&gt;
&lt;li&gt;Sharing needles or other injection equipment&lt;/li&gt;
&lt;li&gt;Sexual exposure involving a partner with HIV who does not have sustained viral suppression, or a partner whose HIV status is unknown.&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;(Note: Under &lt;a href=&quot;https://bhiva.org/clinical-guideline/pep-guidelines/&quot;&gt;&lt;strong&gt;BHIVA guidelines&lt;/strong&gt;&lt;/a&gt;, PEP is generally not recommended if the HIV-positive partner has a confirmed, sustained undetectable viral load on effective treatment, as there is zero risk of sexual transmission.)&lt;/p&gt;
&lt;p&gt;PEP may also be recommended after certain occupational exposures, such as a needlestick injury in a healthcare setting. Occupational PEP is assessed according to specific workplace exposure guidelines.&lt;/p&gt;
&lt;p&gt;PEP is not intended for ongoing or frequent exposure. If you find yourself needing PEP repeatedly, speak with a healthcare professional about whether PrEP could provide more suitable ongoing protection.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Getting Started on PEP&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;During a PEP assessment, a healthcare professional will typically:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;Assess the type and timing of the possible HIV exposure.&lt;/li&gt;
&lt;li&gt;Perform an HIV test, while recognising that PEP should not be delayed unnecessarily while waiting for results.&lt;/li&gt;
&lt;li&gt;Test for pregnancy when clinically relevant.&lt;/li&gt;
&lt;li&gt;Check kidney function and other laboratory markers when indicated.&lt;/li&gt;
&lt;li&gt;Assess for other sexually transmitted infections and hepatitis.&lt;/li&gt;
&lt;li&gt;Review current medicines and possible drug interactions.&lt;/li&gt;
&lt;li&gt;Prescribe a complete or initial supply of PEP with a clear follow-up plan.&lt;/li&gt;
&lt;/ol&gt;

&lt;h2&gt;&lt;strong&gt;How Effective Is PEP?&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;PEP is expected to &lt;strong&gt;substantially reduce the risk of HIV infection when started promptly and taken as prescribed&lt;/strong&gt;, but it is not 100% effective.&lt;/p&gt;
&lt;p&gt;Starting PEP as soon as possible, taking every dose as directed, and completing the full 28-day course are essential parts of treatment.&lt;/p&gt;
&lt;p&gt;Follow-up HIV testing is also recommended after a potential exposure. Your healthcare provider will advise you on the appropriate testing schedule based on the exposure and the tests used.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Side Effects&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;Side effects vary depending on the medicines used. As noted in the &lt;a href=&quot;https://hivinfo.nih.gov/understanding-hiv/fact-sheets/post-exposure-prophylaxis-pep&quot;&gt;&lt;strong&gt;NIH HIVinfo PEP Fact Sheet&lt;/strong&gt;&lt;/a&gt;, some people may experience:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Nausea&lt;/li&gt;
&lt;li&gt;Fatigue&lt;/li&gt;
&lt;li&gt;Headache&lt;/li&gt;
&lt;li&gt;Diarrhoea&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;These effects are often manageable and may improve during treatment. If side effects are severe or make it difficult to continue taking PEP, contact your healthcare provider rather than stopping treatment on your own. A different regimen may sometimes be appropriate.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Where to Access PEP&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;p&gt;PEP may be available through:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Emergency departments&lt;/li&gt;
&lt;li&gt;Sexual health or HIV clinics&lt;/li&gt;
&lt;li&gt;Urgent care services&lt;/li&gt;
&lt;li&gt;Occupational health services for workplace exposures&lt;/li&gt;
&lt;li&gt;Clinics that provide PrEP and HIV prevention services&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Because PEP is time-sensitive, contact a healthcare provider as soon as possible rather than waiting for a routine appointment.&lt;/p&gt;
&lt;p&gt;If you are unsure where to obtain PEP, a local sexual health service or HIV clinic can direct you to the nearest appropriate service.&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;h2&gt;&lt;strong&gt;Frequently Asked Questions&lt;/strong&gt;&lt;/h2&gt;
&lt;hr /&gt;
&lt;h3&gt;&lt;strong&gt;How quickly do I need to start PEP?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;PEP should be started as soon as possible and within 72 hours of a potential HIV exposure. Earlier treatment is preferred, so do not wait until the end of the 72-hour window.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;How long do I take PEP for?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;A standard PEP course lasts &lt;strong&gt;28 days&lt;/strong&gt;. Take the medication exactly as prescribed and complete the course unless your healthcare provider tells you otherwise.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;Is Biktarvy now a preferred PEP regimen?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;Yes. In the United States, the 2025 CDC guidelines list Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) as one of the preferred nPEP options for adults and adolescents without contraindications. Other preferred or alternative regimens may be appropriate depending on individual circumstances and local guidelines.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;Can I take PEP during pregnancy?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;PEP should not be delayed when it is indicated because of pregnancy. A healthcare professional can select an appropriate regimen based on pregnancy status, other medicines, and individual clinical factors.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;Do I need follow-up testing after PEP?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;Current CDC guidance recommends a follow-up contact with a healthcare professional within 24 hours, with follow-up clinical assessment and laboratory testing at approximately 4&amp;ndash;6 weeks and 12 weeks after exposure. The exact testing schedule may vary depending on the individual circumstances and the tests used.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;Is PEP the same as PrEP?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;No. PEP is emergency HIV prevention taken after a potential exposure, usually for 28 days. PrEP is taken before potential exposure and is designed to provide ongoing protection for people who may have repeated or ongoing risk of HIV.&lt;/p&gt;
&lt;h3&gt;&lt;strong&gt;What should I do if it has been more than 72 hours since the exposure?&lt;/strong&gt;&lt;/h3&gt;
&lt;p&gt;PEP is generally not recommended after 72 hours. However, you should still seek medical advice promptly. A healthcare professional can assess the exposure, discuss HIV testing and other STI screening, and advise whether alternative prevention strategies, such as starting PrEP, are appropriate.&lt;/p&gt;

HIV PEP Guide: Emergency Post-Exposure Prophylaxis

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