Men Home > Finasteride Side Effects
Common finasteride side effects may include decreased sex drive, impotence, or decreased ejaculate amount. While most side effects do not require immediate medical attention, some serious problems should be reported to your healthcare provider right away, including breast tenderness; testicular pain; or signs of an allergic reaction, such as unexplained skin rash, wheezing, or hives.
As with any medicine, there are possible side effects with finasteride (marketed under the brand names Propecia® and Proscar®). However, not everyone who takes this drug will experience side effects. In fact, most people tolerate finasteride well. When side effects do occur, they are generally minor and either require no treatment or can easily be treated by you or your healthcare provider.
(The finasteride side effects discussed below are not a complete list of side effects reported with this medicine. Your healthcare provider can discuss a more complete list of side effects with you.)
Proscar has been thoroughly studied in clinical trials, with many people having been evaluated. In these studies, side effects occurring in the group of people taking the drug are always documented and compared to the side effects that occur in a similar group of people not taking the medicine.
Based on these studies, the most common side effects seen with finasteride 1 mg tablets include:
- Decreased libido (sex drive) -- in up to 1.8 percent of people
- Erectile dysfunction (impotence or ED) -- up to 1.3 percent
- Decreased ejaculate amount -- up to 1.2 percent.
(Click Propecia Sexual Side Effects for more information on Propecia, impotence, and these other sexual side effects.)
The most common side effects of finasteride 5 mg tablets include:
- Erectile dysfunction (ED) or impotence -- in up to 18.5 percent of people
- Decreased libido (sex drive) -- up to 10 percent
- Abnormal ejaculation, including decreased ejaculate amount -- up to 7.2 percent
- Breast enlargement -- up to 2.2 percent.
(Click Proscar Sexual Side Effects for more information on the specific side effects seen with Proscar.)
You can also read about other possible side effects by going to the following eMedTV articles:
- Propecia and Weight Gain or Proscar and Weight Gain
- Propecia and Depression or Proscar and Depression
- Acne and Propecia.