I don't know about brushes or anything, but how long were you taking Biotin?
I lost quite a bit through eating low-carb, so I started supplementing with a high-dose biotin, and obviously added back in the carbs. I mean, it does take a while for new hair to grow back in, and I have long hair. The new growth is 1/3 of the way down now, after about a year.
My hair stylist is always thrilled to see the progress.