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
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.
Greetings Josh
I had unprotected sec with a hiv positive male for like 10 times and of those times , he never cum inside me ……. I realised abit later he was hiv positive and not on treatment so I couldn’t get any pep
So I waiting for almost seven weeks after our last sex to test for hiv , I did a rapid antibody at home test , I did 3 of them and they turned out still negative …
I’m worried please what are my chances of it turning positive after 12 weeks
Please help!!!!
Shay
Hi Gira, to confirm your status after an exposure you need to wait 6 weeks after the last dose of PEP. This will require using a 4th generation antigen/antibody test.
Testing: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hey, I had sex with a lady who turned out to be positive in the morng when we went for testing, I took prep after 23hrs and later changed to pep after 43hours of exposure,.. We had long sex, we had 3 shots the whole night of almost 45mins each,… After finishing pep, it’s now 30days after exposure and am still negative,… How safe am I? And am I allowed now to sleep with a negative person without Condom now?
Hi Kiara, what is the type of test you have used?
If this is a 4th generation test your result is conclusive. If you are using a 3rd generation test (usually these are the at home tests) you will need to wait the 12 weeks.
Having sex with someone HIV positive does not mean you are guaranteed to be HIV positive also. There are a number of factors that change this risk e.g., type of sex, how long the sex was and even how rough the sex was. In the meantime are you able to speak with anyone about how you are feeling?
Feeling anxious around testing: https://i-base.info/guides/testing/hiv-testing-feelings-of-fear-anxiety-and-guilt
Hy Josh
I have been intimate with a man for nearly four months , only after those months he opened out he was hiv positive not on medication , yet everytime we had sex he’d cum inside me and also we did it for those 4 months
I’ve been dealing with Anxiety , I tested at 4 weeks after he told me , I’m still negative
Tested again at home at 6 weeks , I’m still negative
How likely is it that I will be positive after 12 weeks , please help
Kiara
Hi Chrissy, this depends on the type of test used. A 4th generation test is conclusive after 6 weeks whereas a 3rd generation test will only be conclusive after 12.
For more information about testing please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
You keep stating after 6 weeks that’s a confirmed test but other guidelines say you need to test 12weeks after the 6th week test. Why are the guidelines you are using different
Hi Joe, no you do not need to wait longer. You only need to extend the testing window for as long as you have been taking PEP.
As you only took PEP for 1 week you just need to extend the testing window by 1 week. A4th gen test is conclusive after 6. Being on PEP for 1 week means you would need to extend to 7 weeks which you did. Your result is conclusive.
Hi – Bit of a unique situation. I had an exposure on 9th August 2023. Initially took PEP for 7 days only after freaking out, then decided the exposure wasn’t high risk.
I tested using a 4th gen last week which was negative, 7 weeks after my last dose of PEP and 8 weeks post exposure. My question is, as I did not complete PEP, are my results still conclusive, or do I need to wait longer? I’ve been having some symptoms in line with acute HIV and I’m scared.
Thanks,
Joe
Hi Tyrone, nucleic acid tests are not used to diagnose HIV. Are you able to access a 4th generation antigen/antibody test? At 4 weeks after PEP this will be 95% accurate. The test can then be repeated in 2 weeks which will give a conclusive result.