Concern regarding adverse effects of finasteride is increasing. We aimed to determine the type and frequency of symptoms in men having long-term sexual and non-sexual side effects after finasteride treatment.…The most frequent sexual symptoms…were loss of penis sensitivity (87.3%), decreased ejaculatory force (82.3%), and low penile temperature (78.5%). The most frequent non-sexual symptoms were reduced feeling of life pleasure or emotions (75.9%), lack of mental concentration (72.2%) and loss of muscle tone/mass (51.9%)…Further studies are necessary to investigate the pathophysiological and biochemical pathways leading to the post-finasteride syndrome.
—An observational retrospective evaluation of 79 young men with long‐term adverse effects after use of finasteride against androgenetic alopecia: Androlog, Jan. 13, 2016