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
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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
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March 2014 in “Indian Journal of Dermatology” January 2013 in “e-Jurnal Medika Udayana” 
12 citations
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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
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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
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June 2001 in “PubMed” Finasteride is effective in growing hair and stopping hair loss in men with mild to moderate alopecia.
3 citations
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October 1995 in “International Journal of Dermatology” Finasteride helps treat skin issues like acne and baldness by blocking testosterone conversion.
