If it helps any, I'm just not working my arms. I switched from weights and isometrics to just stretching and calesthenics (no idea how to spell that). Might go back to isometrics for tone after a while, but with the blockers, estrogen and diet changes (swapped foods out according to testosterone / phytoestrogen content), I've noticed myself losing muscle mass pretty steadily, albeit slowly. My arms were incredibly developed, and my forearms are rounding out and softening quite a bit. I'm not sure if there's any scientific connection, but that's my experience.
I'll also add that while my forearms were what I noticed first, my pecs were the first to go (granted, my pecs never could develop well for some reason). Those went down and now my breasts took their place. But what is weird is that my muscles in any given group/region, while reducing (I assume due to lack of scarring FROM working out, as well as just not getting testosterone into their receptors), the individual muscles in those groups/regions are reducing at different rates. My legs are the most noticable for this, where everything is seen from the frontbalong the shin in particular. Weird, but cool, lol.