When the hair loss drug Propecia was tested it required extensive detailed study. All in all the doctors who organised the trial looked at over 1800 men over a year from the age of 18 to 41 all of whom reported mild up to moderate amounts of continuing hair loss. Out of these men around 1200 who had hair loss on the top of the head also took part in extra clinical studies so that overall the complete study period for the Propecia was 5 years.

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.

There are a few side effects for Propecia but they were seen very rarely and it was seen that some men had sexual side effects like a reduced desire for sex, a decrease in the semen amount and in very rare cases a difficulty in getting an erection however these side effects were seen in less than 1 man in 50 (2%) and went away when the Propecia tablets were not administered anymore. Interestingly and to the relief of some of the participants they also went away in the majority of the men who carried on taking Propecia. Because Propecia can affect the blood levels of various hormones that cause hair loss it is important that you tell you docor about the fact that you are using it and especially if you have a Prostate Specific Antigen (PSA) for the checking of prostate cancer.

Other rare side effects noted were a few allergic reactions like a rash, itching, swelling of the lips or face, breast tenderness or enlargement and sometimes testicular pain. If you see any changes in your breasts like lumps or nipple discharge tell your doctor about it. These side effects are very rare will go if you stop using the Propecia hair loss drug. On the whole the vast majority of men had positive results when using Propecia.