Quoted from http://www.reuters.com/article/2012/04/12/merck-warnings-idUSL2E8FCD4P20120412
Sexual side effects added to Merck drug labels
Thu Apr 12, 2012 12:56pm EDT
April 12 (Reuters) - Prescribing labels for Merck & Co's drugs for baldness and enlarged prostate will add reports of sexual side effects that continued after use of the medicines was stopped, U.S. health regulators said.
Labels will be revised for Proscar, which treats symptoms of enlarged prostate, and hair-loss treatment Propecia, the Food and Drug Administration said. The active ingredient in both drugs is finasteride.
The Propecia label will now include notification of problems with libido, ejaculation and orgasms that continued after use of the drug was ended. Proscar's label will include notification of decreased libido.
The labels of both drugs will also include a description of reports of male infertility and poor semen quality that normalized or improved after use of the drugs was stopped.