Above, Dr. Jerry Shapiro discusses finasteride side effects.

Finasteride is a prescription medication used to treat hereditary hair loss.

Being curious—or even concerned—about finasteride’s side effects is completely fair. Before you take any medication, you should always do your research and make sure you’re comfortable with your treatment plan.

Some of the potential side effects include:

  • dizziness
  • weakness
  • feeling like you might pass out
  • headache
  • runny nose
  • rash
  • swelling in your hands or feet
  • swelling or tenderness in your breasts
  • impotence
  • decreased sex drive
  • decreased semen volume

Let’s just jump right into what’s likely your biggest fear: taking finasteride will disrupt your sex life.

Though rare, in clinical trials, 3.8% of male patients noticed some form of sexual side effects (versus 2.1% of patients using the placebo), including less desire for sex, difficulty in achieving an erection, or a decrease in the amount of semen released during sex. This may continue after stopping treatment.

The number to focus on there is 3.8%. It’s small. Now, that’s not to diminish your concern or to say that the 3.8% people experiencing these symptoms don’t matter—but rather to point out that this isn’t a guaranteed side effect. Despite what you may hear, for 96% of men, taking finasteride doesn’t mean you have to choose between your sex life and your hairline.

Plus, it’s important to note 2.1% of men using the placebo experienced the same side effects.

With that said, you should make the decision that’s right for you. And to do that, we always recommend contacting your doctor if you have questions about side effects. You may also report side effects to the FDA at 1-800-FDA-1088.


The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Finasteride is an oral medication used to treat male pattern baldness in men only. It is not for use by women. When used by men, finasteride is generally safe but it can also cause serious side effects, including but not limited to allergic reactions, sexual dysfunction, and high-grade prostate cancer. Most patients find that problems with sexual function resolve when they stop taking the medicine. For full prescribing information, view the drug label information. For full prescribing information, view the drug label information.