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PEP in Houston: Emergency HIV Prevention Within 72 Hours

Updated · Sources are cited in the text

PEP in Houston: Emergency HIV Prevention Within 72 Hours

This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

If you think you may have been exposed to HIV in the last few days, time matters. PEP, short for post-exposure prophylaxis, is emergency HIV medication that a clinician can prescribe to lower the chance of HIV taking hold after an exposure.

The CDC says PEP should start as soon as possible, and no later than 72 hours after the exposure. This guide walks through what to do, who to call in Houston, and what follows after the first visit.

You do not need to have everything figured out before you go. A clinician will ask the questions and decide whether PEP makes sense for you.

What PEP is, in plain words

PEP is a short course of HIV medicine started after a possible exposure. It is not a vaccine, and it is not a replacement for ongoing prevention.

The CDC describes the course as lasting 28 days. A clinician chooses the specific medicines and tells you how to take them. This article does not cover medicine details because they depend on your health, your other prescriptions and the type of exposure.

PEP is meant for emergencies. For ongoing protection, clinicians use a different approach called PrEP, which we cover near the end.

Who clinicians consider for PEP

The CDC says PEP is for people who may have been exposed to HIV in a single event. That can include condomless sex, a condom that broke or slipped, sexual assault, sharing needles or other drug injection equipment, or a needlestick injury.

Anyone of any gender or orientation can need PEP. Only a clinician can judge whether a specific situation calls for it, so the useful move is to ask.

Materials you will need

You can go without any of these items. They simply make the visit smoother.

  • The time of the exposure. Write down the date and the best estimate of the hour. The 72-hour window is counted from then.
  • A short description of what happened. Clinicians ask in a matter-of-fact way. Your answers help them choose the right care.
  • A list of your current medicines. Include supplements and anything prescribed for you, since some medicines interact with each other.
  • Any health conditions you know about. Kidney or liver problems and pregnancy matter for medicine choices.
  • Insurance information, if you have it. If you do not have insurance, say so at the start so staff can explain the options.
  • A phone you can answer. Follow-up visits and test results are usually arranged by phone.
  • A pharmacy you can reach quickly. Ask the clinician whether the medicine can be provided at the visit or must be picked up.

Step-by-step: how to get PEP in Houston

Step 1: Note the time and act right away

Start by checking the clock. The CDC window for PEP is 72 hours, and starting sooner within that window is better.

If you are close to the edge of the window, or you are not sure how many hours have passed, go to an emergency department rather than waiting for a clinic to open. Staff there can still evaluate you.

Step 2: Choose where to go based on the hour

Your options depend on what time it is and how much of the window is left.

At any hour, including nights, weekends and holidays: go to a hospital emergency department. Tell the triage staff you are there about a possible HIV exposure and that you are asking about PEP. Emergency departments are open around the clock. The Houston Health Department's pages do not list specific emergency departments for PEP, so call the hospital ahead if you want to confirm what it offers.

During clinic hours, with some time left in the window: these Houston clinics list PEP as a service.

The Houston Health Department says its sexual health clinics moved to appointment-encouraged scheduling on September 1, 2026. Walk-ins are still seen as capacity permits, but a walk-in visit is not guaranteed. For PEP, call 832-395-9800 first and say it is time-sensitive. The department's pages do not list clinic hours for these three sites, so ask when you call.

Legacy's page does not state a price for PEP. Ask about cost when you call, and say if you are uninsured. Legacy says its services are open to all regardless of ability to pay. The Houston Health Department lists its health centers as sliding scale.

Step 3: Call ahead if the clinic route is possible

A two-minute call can save a wasted trip. Here is a simple script.

  • "I may have been exposed to HIV about (number) hours ago. Can I be seen today for PEP?"
  • "Do I need an appointment, or can I walk in?"
  • "What should I bring, and what will it cost?"

If the clinic cannot see you in time, ask where they suggest you go. Then head to an emergency department.

Step 4: Tell the clinician what happened

Share the timing, the type of exposure and anything you know about the other person's HIV status. Clinicians hear these stories every day and do not judge them.

If you are not able to say much, that is fine. Say what you can. The clinician will ask follow-up questions.

Step 5: Expect baseline testing

The CDC's guidance for PEP includes an HIV test before or at the start of treatment. A clinician may also order other tests, such as for kidney function, and may offer tests for other sexually transmitted infections.

Testing should not delay the first dose of PEP when the window is closing. Tell the clinician if you are worried about time.

Step 6: Get the prescription and ask how to take it

If the clinician prescribes PEP, ask these questions before you leave.

  • How do I get the full 28-day course, and what if the pharmacy does not have it?
  • What side effects are common, and which ones mean I should call?
  • What should I do if I miss a dose or vomit after taking one?
  • Are there medicines or supplements I should avoid?

Write down the answers or ask for them in writing. Take the medicine exactly as the clinician explains.

Step 7: Finish the course and keep the follow-up visits

The CDC describes PEP as a 28-day course. Finishing it as prescribed matters, so tell your clinician early if side effects make that hard. They can often adjust the plan.

Follow-up visits are part of PEP, not an optional extra. Expect check-ins about side effects and repeat HIV testing after you start. The CDC guidance calls for HIV testing in the weeks and months after an exposure, and your clinician will set the exact dates.

Step 8: Plan your longer-term prevention

Before the course ends, ask whether PrEP might fit your life. PrEP is HIV prevention medicine taken before possible exposures, and the CDC says clinicians may discuss it with people who finish PEP and may be exposed again.

The Houston Health Department offers PrEP and nPEP at each of its health centers, with appointments at 832-395-9800. Legacy Community Health and the Harris County Public Health Antoine Clinic also list PrEP. Texas DSHS keeps a directory of PrEP providers across the state.

Tips and common mistakes to avoid

  • Waiting until morning to decide. The window runs on the clock, not on business hours. If it is late and you are within 72 hours, an emergency department is a reasonable choice.
  • Waiting for a test result first. A person cannot learn from a test taken right after an exposure whether HIV has taken hold. Do not wait for results before asking about PEP.
  • Stopping early because you feel fine. Feeling fine does not tell you whether the medicine has done its job. Ask your clinician before changing anything.
  • Skipping follow-up testing. Later tests are how a clinician checks the outcome. Put the dates in your phone.
  • Using leftover or borrowed medicine. PEP needs a clinician's evaluation and a prescription written for you.
  • Assuming a clinic is open or has PEP in stock. Call first, and check the hours with the clinic or the Houston Health Department.
  • Feeling embarrassed. Clinicians ask about exposures so they can help. Nothing you say will shock them.

If you are under 18

Texas Family Code Sec. 32.003 lets a minor consent to diagnosis and treatment of a reportable infectious disease, and the Texas DSHS HIV/STD Program says that includes HIV. Parent or guardian consent is not required for that care.

The same statute lets a physician tell a parent or guardian about the treatment, with or without the minor's consent. So a clinic cannot promise that a parent will never be told. If privacy is a concern, ask the clinic how it handles it before you share details.

Houston Health Department also notes that a Texas law that took effect September 1, 2025 gives parents and guardians access to a minor's electronic health record. Ask about that too.

What results to expect

The CDC says PEP can lower the chance of HIV infection when it is started promptly and taken as prescribed. It does not work in every case, and no prevention method can promise a result.

Many people have mild side effects such as an upset stomach or tiredness while taking PEP. A clinician can explain what to expect with your specific medicines and when to call.

The only way to learn the outcome is follow-up HIV testing. A clinician will review those results with you. If a later test is positive, HIV is treatable, and people who start treatment can manage it and stay well. Your clinician can connect you with care.

Local context can be a reason to act quickly, not a reason to worry. The Houston Health Department's HIV in the Houston Area 2026 Epidemiologic Supplement reports 1,343 new HIV diagnoses in Houston/Harris County in 2023, a rate of 27.5 per 100,000 people. Prevention tools like PEP and PrEP are available locally for exactly this reason.

After the emergency: testing and support

Follow-up HIV testing can happen through your PEP clinic. Other free testing sites exist too, and some are useful for extra tests between visits.

  • The Montrose Center, 401 Branard Street, Houston, Texas 77006, phone 713-529-0037, lists free walk-in testing Monday through Thursday, 9AM to 2PM. It offers rapid HIV, hepatitis C and syphilis testing. It does not list PrEP or a full STI panel.
  • Avenue 360 Health & Wellness lists free walk-in rapid HIV, hepatitis C and syphilis testing at its Heights and Midtown clinics, Monday through Friday, 8:30AM to 4:30PM. Call (713) 426-0027.
  • Harris County Public Health's Antoine Clinic, 5815 Antoine Dr, Houston, TX 77091, phone 832-927-7350, lists free HIV, syphilis, gonorrhea and chlamydia testing. Its page lists Friday as closed, so confirm hours before you go.

Ask your PEP clinician whether testing elsewhere can stand in for a scheduled follow-up. Some follow-up tests may need to be done through the prescribing clinic.

For a full list of places to get tested in the city, see our guide to STD testing in Houston. You can also find testing sites by ZIP code at gettested.cdc.gov.

An exposure to HIV can also mean exposure to other infections. A clinician can talk with you about testing for syphilis, gonorrhea, chlamydia and hepatitis, and about whether any of them need their own follow-up.

A quick checklist

  1. Write down when the exposure happened.
  2. Decide within the hour whether to go to an emergency department or call a clinic.
  3. Call 832-395-9800 if the Houston Health Department clinics fit your timing.
  4. Bring your medicine list and any insurance information, if you have it.
  5. Take the full 28-day course exactly as prescribed.
  6. Keep every follow-up testing visit.
  7. Ask about PrEP before the course ends.

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