This insightful information was posted on our hair restoration forum by Dr. Paul Shapiro of Bloomington, MN who is a member of the Coalition of Independent Hair Restoration Physicians.
The studies on Propecia, (finasteride 1mg pill) for hair loss treatment were done at the 1mg dose so we do not have any good medical studies to suggest the .5mg will or will not work. I always suggest that anyone taking finasteride for the first time do it as suggested: at the 1mg dose and keep constant for 1 year. Then after you and your physician have a good idea of how effective Propecia has been you can start to adjust the dose if need be.
If you start on the .5mg dose and do not have a good response how will you be able to tell if the poor response was due to the low dose or you are just one of the few (10%) of men it does not work for?
As for the side effects: They are so rare at the 1mg dose I don’t think there would be a statistically significant difference between the 1mg and the .5mg dose.
Prior to doing hair transplants I worked as a Family Doctor until 2000. In my practice we used Proscar, (finasteride 5mg) and it was rare to see side effects even at the higher 5 mg dose.
At the 1mg dose in our practice at Shapiro Medical Group we see the sexual side effects rarely. I have had a few patients stop it because of sexual side effects. As for the possible gynecomastia (breast enlargement) I have only had one patient who may have had the beginning of gynecomastia. He had some breast tenderness and we stopped the Propecia immediately and the pain went away. I have never seen any actual breast enlargement while a patient was taking finasteride.
I hope this information is helpful.
Paul Shapiro, MD