TLDR Finasteride caused bleeding in a man, which stopped after stopping the drug.
A 38-year-old man experienced haematuria and haematospermia during treatment with finasteride for progressive scalp hair loss. He had previously experienced a similar event while taking finasteride. The bleeding stopped completely within 48 hours of discontinuing finasteride, and re-challenging with the drug caused the bleeding to recur. The adverse drug reaction was considered a "definite" reaction according to probability criteria.
2 citations,
October 2017 in “Drug safety - case reports” Finasteride for hair loss may cause painless bleeding in urine and semen.
November 2020 in “Journal of The American Academy of Dermatology” Finasteride 1 mg every other month works as well as daily dose for hair loss maintenance.
5 citations,
March 2014 in “Indian Journal of Dermatology” January 2013 in “e-Jurnal Medika Udayana” 
12 citations,
August 2004 in “PubMed” Finasteride, especially in a 1mg dose, effectively slows hair loss and improves hair growth in Japanese men with male pattern hair loss.
38 citations,
June 2003 in “Journal of Investigative Dermatology Symposium Proceedings” Finasteride effectively improves hair growth and slows hair loss in men with male pattern baldness.
10 citations,
June 2001 in “PubMed” Finasteride is effective in growing hair and stopping hair loss in men with mild to moderate alopecia.
3 citations,
October 1995 in “International Journal of Dermatology” Finasteride helps treat skin issues like acne and baldness by blocking testosterone conversion.
