Question
Is a negative HIV test four weeks after PEP okay?
7 June 2023. Related: All topics, HIV testing, PEP/PEPSE, South Africa.
Good day.
Is it possible to test positive after testing negative after completing 28 day of PEP?
Answer
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.
I test hiv antibody only (3rd gen) 12 weeks after pep come back negative but I have symptoms of seroconversion like fever, joint and muscle pain, retro orbital pain, and few rashes on my body which appear scattered ( one-one) . what can be this?
Hi Raju, pls see this link to info about PEP that answers these Qs and explains you are negative:
https://i-base.info/qa/factsheets/pep-faq
Hi I do sex with man I am bottom and condom will broken after 1 min he changed the condom but sperm not go inside I don’t know about pre cum then after 18 hours I take pep now after exposure 112 days and after finshed pep 84 days I tested with 3rd gen kit and I go negative how much test is accurate and how much chance I get postive in future in my these condition please reply
Hi Pikay, a 3rd generation test will be conclusive 12 weeks (90 days) after the last dose of PEP.
More information about testing can be found here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
For conclusive results , can i test with 3rd generation test after 9 weeks of pep?
Hi Alex, a viral load test is not used to confirm HIV status. A viral load test can detect other infections and provide false HIV results.
An antibody test is required to confirm HIV status. The earliest you can do this is with a 4th generation antigen/antibody at least 6 weeks after the last dose of PEP.
Please see here for more information about testing: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hello Josh, after last dose of PEP, May i get the test with RNA PCR viral load test? (4 weeks after)
I have seen many comments saying that RNA PCR is not recommended? Why sir? I am now 36 days after the last PEP dose, and I have just experienced a sore throat, is it telling me i am starting to have symptoms? Thank you
Hi Aayush, an antigen test 12 days after PEP will not be conclusive.
The only tests used to confirm HIV status is antibody tests. A combined 4th generation test will be conclusive from 6 weeks after the last dose of PEP. A 3rd generation (only antibody) will be conclusive from 12 weeks after.
Any other test cannot be used to determine HIV status.
For more information about testing please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Can I take an antigen test 12 days after finishing PEP? Will it be conclusive?
Hi Aarif, using a 4th generation test 6 weeks (42 days) after the last dose of PEP will give a conclusive result.
More information about testing and transmission can be found here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing