Important Safety Information for Finasteride

This information is not comprehensive. Please see the full Prescribing Information for complete safety information.

In case of emergencies, please call 911 or go seek care at the nearest emergency room. Tell your care team right away about any side effects that bother you. If you experience adverse side effects, you can report them to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

What is the FDA-approved use of finasteride?

Finasteride is a 5α-reductase inhibitor approved to treat male pattern hair loss (androgenetic alopecia) in men only.

This medication is not approved for women or children.

Who should not use finasteride?

Do not use finasteride if:

  • You are a woman, are pregnant, or may become pregnant. Women should not take finasteride or handle crushed or broken tablets. In animal studies, finasteride caused abnormal development of the genitals in male fetuses.
  • You have had an allergic reaction to finasteride or any of its ingredients.

How should I take finasteride?

You can take finasteride with or without food.

In general, three months or more of daily use is needed before you notice an improvement in hair loss. If you're not seeing a difference after three months — or you have any questions about changing or stopping the medication — message your care team for guidance.

What should I tell my provider before taking finasteride?

Tell your provider about all of the medications you take, including prescription and over-the-counter medicines, vitamins, and herbal or dietary supplements.

Share your full medical history. In particular, tell your provider if you have a history of:

  • Prostate cancer
  • Depression
  • Suicidal thoughts or behavior

Withholding or providing inaccurate information about your health in order to obtain treatment may result in harm, including, in rare cases, death.

What are the most serious risks I should know about?

If you are experiencing a medical emergency, call 911 or seek immediate medical attention.

  • Effects on PSA levels: Finasteride can lower prostate-specific antigen (PSA) levels. If you have a PSA test, tell your provider you take finasteride so the results can be interpreted correctly. A PSA test is used to screen for prostate cancer.
  • Increased risk of high-grade prostate cancer: In two studies of 5α-reductase inhibitors used to help prevent prostate cancer, an increase in high-grade prostate cancer was observed.
  • Fertility: Oral finasteride has been linked with a reduction in sperm count. This can last up to 6 months after stopping. Men with a history of fertility issues should discuss this with their care team before starting.
  • Mood changes / depression / suicidal thoughts: There may be evidence of increased depressive symptoms, anxiety, and thoughts of suicide in users younger than age 45 taking finasteride for hair loss. If you experience new or worsening depression or suicidal thoughts, stop taking this medication and contact your care team or a mental health professional right away.

What are the most common side effects of finasteride?

The side effects men report most often are sexual:

  • Lower sex drive
  • Erection problems
  • Less semen when you ejaculate