When it comes to hair loss avoid all DHTs which include winny, masteron, var, ect. In addition testosterone and many other derivatives will convert to DHT via the enzyme 5-alpha-reductase, this converts testosterone to dihydrotestosterone (DHT) in peripheral tissues. When taking test, et al use a 5-alpha-reductase inhibitor like finasteride(Proscar, Propecia) or dutasteride. These compounds are also used to mask steroid use in drug test since most test look for the metabolites.

Hope this helps!