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Has past PEP use affected my 12 week Hiv reading ?


Hi there,

I had an exposure on March 7th, 2016.. I tested up until June 1st, 2016 which makes it around 86-87 days, which is around 12 weeks and it came back negative. I did not use PEP for this exposure. I should add that it was with a sex worker and I used protection and it did not break. I was happy to take the negative result as conclusive until I read that if you have used PEP in the past it might delay the reading and I might have to wait up to 6 months for a conclusive result. I used PEP on two occasions in the past and adhered to the regimen and tested up to 6 months for each time. Does that mean my 12 week Neg for this exposure part can be wrong? I am only worried because I am scared that I may have aquired HIV despite condoms, from the base of my penis, through small cuts, undiagnosed herpes, or syphilis or something.

Please let me know. Will past PEP usage affect my 12 week negative result from the tests done at a reputable sexual health clinic here in Australia ?


Hi there, and thanks a lot for contacting the AIDS Vancouver Helpline for your HIV/AIDS related health information. It seems you have some questions about PEP. We're happy to answer your question for you.

PEP does extend the window period for as long as it is taken after a potential exposure. For example, if you had an exposure on day 0, normally you'd be able to go for testing on day 90. PEP regimens are usually 30 days in duration, so extend the window period by 30 days. In that case, you'd be able to go for testing 120 days post exposure. We think what the statement means is that some people, for various reasons, may be on longer PEP durations, so their window periods may be extended up to 6 months. Since you have not taken PEP since your potential exposure, your last test at around 90 days is conclusive of your status and you are presently HIV negative (should you not have had any other potential exposures in the meantime).

Thanks for contacting the AIDS Vancouver Helpline with your question, we hope it has been answered fully.


AIDS Vancouver Helpline/Online