There is no doubt that Propecia works. In short it was seen that the men who used Propecia maintained or sometimes actually increased the amount of visible hairs on the scalp and saw a marked improvement in hair sometime in the 1st year. The hair loss continued to stop and in somecases the improvements were seen to continue right to the endof the study that went on for 5 years. A control group who dod not take Propecia continued to see more hair fall out. The study showed that Propecia would only grow hair on the scalp and not in any other part of the body.
The Propecia results are not the same for all men and it is important to know that Propecia will not regrow bald spots but it is likely to slow down the hair loss and stop it getting worse. Propecia seems to work best with balding on the top of the head and the evidence that Propecia stops a receeding hairline has not been verified.
If the results are not noticeable after 4 months of taking Propecia then it is possible that it doesn't affect you as it does others, and you should move on to another hair loss medication. However, Propecia has been proven in numerous trials and studies to show considerable hair growth improvements in 4 out of the 5 individuals that took it.