Health Canada

Health Canada

August 04, 2011 09:46 ET

Finasteride (Propecia, Proscar): Potential Rare Risk of Breast Cancer in Men

OTTAWA, ONTARIO--(Marketwire - Aug. 4, 2011) - Health Canada is informing healthcare practitioners and patients of a labelling update for finasteride drugs to add safety information on rare reports of breast cancer in men.

Finasteride is a prescription drug sold in Canada under two brand names, "Propecia" and "Proscar." Generic finasteride products (1mg and 5mg) are also available on the market. Propecia (1 mg tablets) is used for the treatment of male pattern hair loss, while Proscar (5 mg tablets) is used in the treatment and control of benign prostatic hyperplasia (BPH), which is a non-cancerous enlarged prostate. Finasteride is for use in men only.

Male breast cancer has been reported in a small number of patients worldwide with both the 1 mg and 5 mg formulations of finasteride. Most of the reports have been in association with the 5mg formulation. Based on the currently available evidence, it is not known with certainty whether finasteride can cause breast cancer, nor can this possibility be ruled out at this point in time.

The labelling for Propecia, Proscar and several of the generic finasteride products has already been updated to include information on the potential risk of male breast cancer. Updates to the remaining generic drugs will follow.

Patients taking finasteride should report any changes in their breasts to their doctor. Changes might include breast enlargement, lumps, tenderness, pain or nipple discharge.

Patients with questions or concerns about their finasteride treatment should talk to their health professional. Drug labels, or "Product Monographs," contain important prescribing and safety information for health professionals and patients, and are available by search of Health Canada's Drug Product Database (

How to report side effects to health products

To report suspected side effects to these or other health products, please contact Health Canada's Canada Vigilance Program toll-free at 1-866-234-2345, or complete a Canada Vigilance Reporting Form ( and send to us using one of these methods:

  • Fax: 1-866-678-6789
  • Internet:
  • Mail: Canada Vigilance Program
    Marketed Health Products Directorate
    Ottawa, ON, Address Locator 0701E
    K1A 0K9

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