heres a study on proviron..still lookin on the primo:
Oral synthetic 17-a alkylated androgens such as methyltestosterone (96), fluoxymesterone (97), methandienone (98) and danazol (99, 100) suppress spermatogenesis but azoospermia is rarely achieved and the inherent hepatotoxicity of the 17-a alkyl substitutent (101) renders them unsuitable for long-term use. Athletes self-administering supratherapeutic doses of androgens also exhibit suppression of spermatogenesis (98, 102). Synthetic androgens lacking the 17-a alkyl substituent have been little studied although injectable nandrolone esters produce azoospermia in 88% of European men (103, 104) whereas oral mesterolone is ineffective (105). On the other hand, nandrolone hexyloxyphenylpropionate alone was unable to maintain spermatogenic suppression induced by a GnRH antagonist (106) in a prototype hybrid regime (where induction and maintenance treatment differ) whereas testosterone appears more promising (107). A 7-methyl derivative of nandrolone (MENT), which is partly aromatisable but resistant to 5α reductive amplification of androgenic potency, has been studied as a non-oral androgen for hormonal male contraceptive regimens (108). While it is prostate-sparing (109), dose titration to achieve essential androgen replacement at each relevant tissue is more complex than for testosterone and may be difficult to achieve (110). More potent, synthetic androgens lacking 17-a alkyl groups (111, 112) remain to be fully evaluated.
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