@Cicero Not sure if brittle is the technically accurate term to use, but I've seen others describe it as such when talking about having low E symptoms from Andro and AI's.
My symptoms were cracking and aching joints, which is in line with what (some) others experience when having low E for a sustained amount of time (surprisingly, from all the accounts I've read of people taking AI's, aching joints is not commonly cited as a side effect). I'm positive my excessive dosing of andro caused this because I was on nothing else at the time, and taking 1 week off andro reversed the symptoms.
As I understand it, Estrogen is a regulator of bone stability.
I was still active at the time and suffered no injuries while having these symptoms, so again, brittle may not be the most accurate way to describe this - but the aching feeling was certainly uncomfortable.