I was on Propecia for a year before I switched to avodart this month. About 7 months in I went off propecia and my multivitamin for about 2-3 weeks (actually it was spotty/intermittant) and basically lost the hair that I'd recovered during that time. After I got back on it religiously I began recovering it.
After taking Propecia for a couple of months, little blond hairs appeared where I'd been thinning to my widow's peak, but they never managed to do much besides grow a little then fall out. They're back again, thank god, and I'm hoping they'll stay and thicken up now that I'm on avodart.
What I personally found was that propecia was not enough. I was losing a handful of hair each shower when I was off my multivitamin, after getting back on it, I typically lose less than 6 hairs per shower. Going from actually balling up a wad of hair in my palm to sticking 3 hairs on the wall is fantastic.
Also during my anorexia phase I lost a tremendous amount of hair to poor diet and stress. Be sure you're eating as healthy as you can, lack of nutrients causes hair to go into crisis.
I swear that my bodyfat distribution is different than it was pre-propecia, but I have no proof. It just feels like my body looks more feminine.