Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you notice any signs of male breast cancer, such as:
breast lumps;
breast pain or tenderness;
nipple discharge; or
any other breast changes.
Common side effects may include:
loss of interest in sex;
impotence;
trouble having an orgasm; or
abnormal ejaculation.
The sexual side effects of finasteride may continue after you stop taking  finasteride. Talk to your doctor if you have concerns about these side effects.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Finasteride side effects (more detail)
