I had fantastic results when I started taking propecia 11 years ago. I had none of the side affects, and my thinning hair stopped in its tracks. I was the perfect age at the time (28) as my hairloss was in the minor thinning phase. Propecia certainly prevented further loss/thinning. Fast forward to today, and Propecia is just not as effective as it was before. A few years ago I started getting diffused thinning at the crown and hairline. I still have satisfactory coverage in those areas, but I don't have the same density as before. There have been no long term studies on Propecia, so I'm thinking at some point genetics take over and the hair loss resumes. I'm still currently taking Procepia, as I believe it is at least keeping the hairloss at a slower pace.