Although Propecia is mainly used to keep the hair you have from falling out, there are people who have regrown some of the hair they've lost when using Propecia combined with rogaine. When using Propecia, you'll shed some hair, but it should grow back stronger.
Using Propecia and Rogaine together works really well for some in regrowing hair, but for others only stabilizes the hair loss, which isn't a bad thing either.
I have read posts about people having some sexual side effects from Propecia. I've been taking Propecia for about a month and a half and I'll admit, when I first started taking it, my testicles got pretty sore and it didn't seem like I was having as good of an orgasm.(sorry if that's a little too much info, but I'm letting people know what it can do). I started cutting the pills in half, and then started taking them every other day till the pain in my testicles subsided, and now I'm back on my full dosage everyday. So for me, the side affects did subside, I guess my body just needed to adjust to the drug.