Question

Is a negative HIV test four weeks after PEP okay?

7 June 2023. Related: All topics, HIV testing, PEP/PEPSE, Southern Africa.

Good day.

Is it possible to test positive after testing negative after completing 28 day of PEP?

Answer

Answer: Simon Collins

Hi

In the UK, people need to wait 4 to 6 weeks after the last dose of PEP before taking a 4th generation HIV antigen/antibody test.

If this test is negative after 6 weeks, then someone is told they do not have HIV. If it is negative after 4 weeks, it means HIV is unlikely, but that a second test should confirm this after a few more weeks.

There is no point taking an HIV test as soon as you finish PEP.

This is because the PEP could just be covering up or delaying a potential infection.

This answer was updated in June 2023 from a question first posted in November 2020. This is because UK guidelines now recommend testing after 6 weeks rather than after 4 weeks.

Please see this link for more information about PEP:
https://i-base.info/qa/factsheets/pep-faq

Simon.

281 comments

  1. James •

    Hello – I have received a negative result 6 weeks after completing a course of PEP. The test was a vein test done at a GUM clinic in UK (so I think this would be a 4th generation one, was sent to the lab). Do I need to test again at 12 weeks to be safe?

  2. Josh Peasegood •

    Hi Zack, Truvada is used as PrEP. It is not a combination used for PEP. It does contain some of the same medication but PEP uses a combination of 3 drugs, whereas Truvada only contains 2: emtricitabine and tenofovir.

  3. Zack •

    And I used only Truvada or Mylan.

    How many percent chance does that stand to work as PeP ?

  4. Josh Peasegood •

    Hi Zack, a test after 2 days is not conclusive. The earliest test you can take to be sure is a 4th generation antigen/antibody test. This test will be conclusive 6 weeks after finishing PEP.

  5. Zack •

    A test 2days after PeP…..is that a conclusive one ?

  6. Josh Peasegood •

    Hi Kitto, yes this test is conclusive. As you have waited 12 weeks after PEP you can consider this test conclusive. You do not have HIV.

  7. Kitto •

    12 weeks after pep I did a rapid antibody hiv blood test and came out negative.
    Can I throw this issue aside now?

  8. Josh Peasegood •

    Hi Zokay, your test is conclusive. As it has been 6 weeks since you finished your course of PEP, it is confirmatory. You are HIV negative.

  9. Zokay •

    6 weeks after Pep I did a 4th generation rapid HIV test in an HIV test center and it was negative. can i close

  10. Josh Peasegood •

    Hi Zokay, in the UK a test 6 weeks after PEP is considered conclusive. After 5 weeks it is very likely to remain negative but a follow up test a week later would be able to completely confirm your status.

    0.34 is a vale used to identify HIV. Any number less than 1 means that you do not have HIV. You can follow this link to read more: https://i-base.info/guides/testing/what-does-a-number-on-my-negative-hiv-test-result-mean