Side effects of Propecia/Finasteride: can they cause breast cancer by men ?
The frequency of breast cancer is very low by men (1 out of 100,000). Some fifty cases of breast cancer by men taking Proscar (5 mg of Finasteride) have been observed. Only three cases around the world have been described as patients taking Finasteride 1 mg (Propecia).
In double-blind studies, the consumption of Finasteride and breast cancer by women have not been related. The Merck company, which is very careful with its warnings, advises to consult a doctor at the least lump or discharge from the nipple. However, patients can be reassured as this kind of consequence is very exceptional.