MANY people have received negative results from finasteride (propecia, proscar) including me. I was on it for 3 and a half weeks and started getting man boobs. Luckily I caught it early and it doesnt look terribly bad yet. I figure if I step up my gym routine and concentrate more on my pectorals I can probably hide what I do have.
NOTE: I was on 1mg for the first 2 weeks, then I found it much easier to cut the proscar into quarters and take 1.25mg for the last week and a half. But Im certain I would have gotten gyno regardless.