proscar (finasteride) works just like propecia - theyre both finasteride.
the reason propecia is sold as 1mg, whereas proscar is 5mg, is that theres not much difference between the effects of 1mg and 5mg. in fact, the difference is very very negligible.
so, upping your dose like that is likely to have little or no effect whatsoever. however, ive studies have shown that the higher the dose, the greater the chances/strength of side effects. thus, more proscar (5mg) users see side effects than propecia (1mg) users.
id suggest sticking with your dose of proscar, but if youre not seeing any results, add minoxidil 5% twice daily, and nizoral 2% shampoo 2-3x per week to your regimen. good luck.