Long term finasteride use

https://www.hgspecialist.com/resources/product-files/files/Finasteride-10-year-follow-up.pdf

of the 113 patients followed for 10 years, only 14% worsened, whereas the remaining (86%) had benefits (21%)
from the treatment duration or (65%) persisted in their improvements. Patients not improved at all
after one year (i.e., with a significant decreasing in their hair growth) could be considered not respondent to a long-term therapy.

Side effects were observed on 5.9% (7) patients, but these effects were not age related (12–14). Some
of the patients who experienced side effects did not drop out of the treatment because of perceived
good results.