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Finasteride

Generic name: finasteride (fin AS ter ide)
Brand name: Propecia, Proscar
Dosage forms: oral tablet (1 mg; 5 mg)
Drug class: 5-alpha-reductase inhibitors

Medically reviewed by Drugs.com on Sep 10, 2021. Written by Cerner Multum.

What is finasteride?

Finasteride is used alone or with other medication to treat symptoms of benign prostatic hyperplasia (BPH) in men with enlarged prostate.

Finasteride is also used to treat male pattern hair loss in men.

finasteride is for use in men only.

Finasteride may also be used for purposes not listed in this medication guide.

Warnings

Finasteride should never be taken by a woman or a child.

Before taking this medicine

You should not use finasteride if you are allergic to it.

Using finasteride may increase your risk of developing a serious form of prostate cancer. Ask your doctor about this risk.

Tell your doctor if you have ever had:

finasteride should never be taken by a woman or a child.

Finasteride can cause birth defects if a woman is exposed to it during pregnancy. A broken finasteride tablet should not be handled by a woman who is pregnant or may become pregnant. The medicine from a broken tablet could be absorbed through the skin.

If a woman accidentally comes into contact with a broken or crushed tablet, wash the area with soap and water right away.

How should I take finasteride?

Your doctor will perform tests to make sure finasteride is the right treatment for you.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take with a full glass of water at the same time each day, with or without food.

You may not fully benefit from this medicine for up to 3 months or longer. Use finasteride regularly for the best results.

Your doctor will need to check your progress on a regular basis. You will need frequent prostate specific antigen (PSA) tests to check for prostate cancer.

Tell your doctor if you stop taking finasteride on a regular basis because this could affect your PSA test results.

Store this medicine at room temperature, away from moisture, heat, and light. Keep the tablets in the original container, tightly closed when not in use.

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking finasteride?

Do not share finasteride with another person, even if they have the same symptoms you have.

Finasteride side effects

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 pain or lumps;

  • nipple discharge; or

  • any other breast changes.

Tell your doctor right away if you have:

  • blood in your semen;

  • pain in your testicles; or

  • depression.

It may be harder for you to get a woman pregnant while you are using finasteride.

Common side effects may include:

  • decreased interest in sex;

  • trouble getting or keeping an erection;

  • trouble having an orgasm;

  • abnormal ejaculation; or

  • breast swelling or tenderness.

The sexual side effects of finasteride may continue after you stop taking this medicine. 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 dosing information

Usual Adult Dose for Benign Prostatic Hyperplasia:

5 mg orally once a day

Comments:
-Dosing is the same both in monotherapy and in combination therapy.

Usual Adult Dose for Androgenetic Alopecia:

1 mg orally once a day

For the treatment of male pattern hair loss (androgenetic alopecia) in men only. (Safety and efficacy have been demonstrated in men between 18 to 41 years of age with mild to moderate hair loss of the vertex and anterior mid scalp area):

Comments:
-Daily use for 3 months or more is necessary before benefit is observed. Continued use is recommended to sustain benefit.
-Withdrawal of treatment leads to reversal of effect within 12 months.

Use: For the treatment of male pattern hair loss (androgenetic alopecia) in men only. (Safety and efficacy have been demonstrated in men between 18 to 41 years of age with mild to moderate hair loss of the vertex and anterior mid scalp area).

What other drugs will affect finasteride?

Other drugs may affect finasteride, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Does Finasteride interact with my other drugs?

Enter other medications to view a detailed report.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.