Forget about Proscar. go for avodart (dutasteride) it's much more potent. It blocks both Type I & Type II enzymes responsible for test to dht conversion.I'm MPB prone. used proscar for 4 years and now switched to Avodart. see here, they have a picture www.buy-avodart.com
U can get generic version called Fincar (5mg) and its dead cheap, I think $35 for 30 tabs, u can break the tab into 4 pieces and take 1 a day, should last u about 17 weeks U cant go wrong!!