Some effects can include:
impotence, loss of interest in sex, trouble having an orgasm, abnormal ejaculation, swelling in your hands or feet, swelling or tenderness in your breasts, dizziness, weakness, feeling faint, headache, runny nose, skin rash.
Speak with your doctor if any side becomes become too severe while taking Proscar. Your doctor and pharmacist will be able to help you manage your side effects.