Hair Restoration Options:
The first study on topical finasteride was done in 1997 and showed a decrease in rate of hair loss at 6 months.
In 2009, another study compared topical finasteride to oral finasteride. This study was a double blind, randomized clinical trial. Both topical and oral led to increased hair counts, although the increase occurred 1 month earlier with oral finasteride. Another difference between the two groups was that the size of the area of hair loss decreased by the fourth month of treatment in the oral finasteride group, whereas there was no significant change in the topical group.
In 2018, Lee et al. reviewed 7 studies that looked at the use of topical finasteride for the treatment of pattern hair loss in men and women. They looked at several concentrations, including finasteride 0.005%, 0.25%, and 1%. The good news is that they all showed some efficacy with limited systemic effects. Overall, topical 0.25% finasteride solution applied once a day seemed to be the most effective. The downside is that topical finasteride did cause some scalp irritation in some participants, which could be a limiting factor for some patients. It is not clear if the irritation came from the finasteride itself or from one of the other components in the solution.