At small doseages, no it will not. My doctor has put men on it for years at a time for low sex drive with no type of PCT - post cycle therapy - when they stopped taking it, and test levels were no different than pre proviron time afterwards. I only stated what more than one doctor has explained to me in the past, I am lucky to have many friends that are physicians, and one an ex body builder that know this stuff inside and out, I trust what he tells me hands down. With that said, none of the above patients were taking more than 25mgs per day, and we as bodybuilders usually use 50-75mgs in a cycle. For that I cannot say for certainty that it would or would not shut you down, but I can speak for the 25mg dose.