Proviron does not suppress testosterone, fsh or lh.

[anabolicmindset]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=2892728&query_hl=5&itool=pubmed_DocSum

According to this study, proviron (mesterolone) does not supress testosterone even after 12 months at 100 to 150mg per day. It only suppressed FSH and LH iin people who had high levels of FSH and LH to begin with. Everyone else had no affect on these. No affect on liver function either.

Heres another study that concludes Proviron does not impair endogenous testsosterone production after it is discontinued.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=883846&query_hl=5&itool=pubmed_DocSum

[Mr.X]

althought the study says that
I can tell you first hand exprience , it does !