Merck's baldness drug Propecia is taken by many American men with thinning hairlines. The drug, known generically as finasteride, is also sold by Merck as a different pill Proscar to treat an enlarged prostate. The U.S. Food and Drug Administration has announced label changes for both drugs, saying they could cause sexual side effects in the men who take them.
http://www.cbsnews.com/8301-504763_162-57413756-10391704/fda-adds-sexual-side-effects-warning-to-baldness-drug-propecia/
