Q and A


Taking PEP 66 hours post exposure.

Is pep effective if taken 66 hours after the exposure? and how effective is it?


Hi there, how are you doing?

PEP is effective as long as it is taken within 72 hours of the exposure. It is most effective within 24 hours, but UK guidelines note that it remains clinically effective until 72 hours. The full effectiveness also requires completing the full 28 day course.

PEP does not offer a guarantee. Studying how effective PEP is is difficult due to ethics. From studies looking back in time, it shows that PEP has an effectiveness between 80-90% depending on the time started and how well the individual complied with the course of PEP.

This is a guide further explaining PEP and links to other related articles.

If you have another question please ask,



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