Finasteride – Oral

What Is Finasteride?

Finasteride is a prescription medication that treats benign prostatic hyperplasia (BPH) under the brand name Propecia and male-pattern hair loss under the brand name Proscar. It is part of a class of medications known as 5-alpha-reductase inhibitors.

Finasteride works by decreasing the amount of hormone dihydrotestosterone (DHT) in your body. By reducing DHT, finasteride can help prevent the prostate from growing larger. It can also increase hair growth and decrease hair loss on your head.

Finasteride is an oral medication available in tablet form. It is available under two brand names and formulations for separate indications: Propecia 1-milligram (mg) tablet for BPH and Proscar 5-milligram tablet for male-pattern hair loss. There is also a generic version.

Drug Facts

Generic Name: Finasteride

Brand Name(s): Propecia, Proscar

Drug Availability: Prescription

Therapeutic Classification: 5-alpha reductase inhibitor

Available Generically: Yes

Controlled Substance: N/A

Administration Route: Oral

Active Ingredient: Finasteride

Dosage Form: Tablet

What Is Finasteride Used For?

The Food and Drug Administration (FDA) has approved finasteride to treat:

  • Male-pattern hair loss, also called androgenetic alopecia
  • Benign prostatic hyperplasia (BPH), a condition caused by an enlarged prostate

Finasteride may be used alone or in combination with another medicine to help treat BPH. It works to reduce symptoms associated with BPH, such as:

  • Difficulty urinating
  • Decreased flow of urination
  • Hesitation at the beginning of urination
  • A need to get up at night to urinate

For male-pattern hair loss, finasteride can help fill in balding or thin areas of hair on the scalp. However, you may not grow all of the hair back that you've lost.

How to Take Finasteride

Finasteride is available as an oral tablet. These are meant to be taken by mouth, often once a day and at the same time every day. This medication can be taken with or without food.

If you are taking finasteride for male-pattern hair loss, be patient and continue to take your medication regularly, as it may take some time to notice hair growth. You might lose any hair you've regrown if you stop taking it. However, if you don't notice any benefit within 12 months of treatment, it is unlikely that this medication will work for you.

Storage

Store finasteride at a controlled room temperature, which is between 68 and 77 degrees F.

People who are pregnant or who may potentially be pregnant should not handle crushed or broken finasteride tablets; absorption of the medication could potentially put the fetus at risk. Because the tablets are coated, normal handling of intact tablets is OK.

How Long Does Finasteride Take to Work?

For male-pattern hair loss, participants in clinical studies experienced an improvement in hair growth as early as three months into treatment. It is recommended to continue using it to see a sustained benefit. However, if you don't see any improvement in 12 months of treatment, this medication might not work for you.

In BPH, people taking finasteride in trials had reduced prostate growth within one year of treatment, which was maintained for five years in additional studies.

What Are the Side Effects of Finasteride?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

The most common side effects of finasteride include:

Studies have reported these effects occurring early in therapy and going away after continued use or once the drug was stopped.

People taking finasteride have noted incidences of skin rash and increased breast size and tenderness. However, these side effects were reported voluntarily from an unknown population size; therefore, their frequency and association with finasteride are unclear.

Talk to your healthcare provider or pharmacist if any of these side effects don’t go away or become more severe.

Severe Side Effects

Call your healthcare provider immediately if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include the following:

Contact your healthcare provider if you experience any of the above-listed side effects.

Report Side Effects

Finasteride may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Finasteride Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For benign prostatic hyperplasia:
      • Adults—5 milligrams (mg) once a day.
      • Children—Use is not recommended.
    • For male pattern hair loss:
      • Adults—1 milligram (mg) once a day.
      • Children—Use is not recommended.

Missed Dose

If you miss a dose of finasteride, take the next tablet at your scheduled time. Do not take extra to make up for the missed dose. Doing so can increase your risk for side effects.

Overdose: What Happens If I Take Too Much Finasteride?

No incidences of overdose have been reported for finasteride. However, you should always take care to only take the prescribed amount.

What Happens If I Overdose on Finasteride?

If you think you or someone else may have overdosed on finasteride, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking finasteride, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

Women and children should not use this medicine. Women who are pregnant or may become pregnant should not handle crushed or broken tablets. Finasteride can be absorbed through the skin and cause birth defects in male babies. If a woman does come in contact with this medicine, the affected area should be washed right away with soap and water.

This medicine will not prevent prostate cancer but may increase your risk of developing high-grade prostate cancer. Tell your doctor if you have concerns about this risk.

This medicine may affect the results of the prostate specific antigen (PSA) test, which may be used to detect prostate cancer. Make sure you tell all of your doctors that you are using this medicine.

Some men who use this medicine have become infertile (unable to have children). Talk with your doctor before using this medicine if you plan to have children.

What Are Reasons I Shouldn’t Take Finasteride?

There are a few reasons why your healthcare provider may not choose finasteride as part of your treatment plan, including the following.

Allergy

A person should not take finasteride if they are allergic to the ingredients. Severe allergic reactions symptoms may include:

  • Hives
  • Swelling of tongue or throat
  • Trouble breathing

Pregnancy

Finasteride can pass through the skin upon direct contact. People who are pregnant or plan to become pregnant should not be in contact with broken or crushed finasteride tablets. It has the potential to cause birth defects. Finasteride is not prescribed for use in women and should not be taken during pregnancy.

Breastfeeding

Finasteride is not indicated for use in women. It is not known if finasteride passes through into breast milk.

Children

This drug is not approved for use in children.

Other Health Conditions

Inform your healthcare provider if you have:

What Other Medications Interact With Finasteride?

Before taking this medication, be sure to tell your healthcare provider about all of the prescription medications, over-the-counter (OTC) medications, vitamins, supplements, or herbs you are taking. This will help you avoid potential interactions. If you have any questions about drug interactions, speak with your healthcare provider or pharmacist.

What Medications Are Similar?

Finasteride is the primary prescription oral medication for the treatment of male-pattern hair loss. However, there are other medications used for hair loss. These include:

Hair transplant is a surgical option for the treatment of male-pattern hair loss.

For BPH, dutasteride is the only other available alpha-reductase inhibitor. Other drugs used to treat BPH that are not part of the same drug class as finasteride include:

Talk to your healthcare provider about what might be the best option for you.

Frequently Asked Questions

  • What is finasteride used for?

    Finasteride is often prescribed to treat male-pattern hair loss. It works by decreasing the hormone DHT, which leads to increased hair growth and decreased hair loss on the head. It can also be used to treat BPH, also known as prostate enlargement. Reducing DHT also prevents further prostate growth.

  • Can women take Propecia?

    No, finasteride is only indicated for use in people assigned male at birth. This medication can also pass through the skin upon direct contact, so people who are pregnant or plan to become pregnant should not handle broken or crushed finasteride tablets.

  • What are the side effects of finasteride?

    The most common side effects of finasteride include decreased sex drive, ejaculation issues, and trouble keeping or getting an erection. It can also cause serious side effects such as swelling of the tongue, lips, or mouth or lumps in the breast. Call your healthcare provider right away if you experience any serious side effects. Call 911 if you are having a medical emergency or life-threatening symptoms.

How Can I Stay Healthy While Taking Finasteride?

Finasteride is a safe and effective medication when used as directed. This drug is often used to treat male pattern hair loss and BPH.

While it does have the potential for severe side effects, the more common side effects are milder and include decreased sex drive, ejaculation problems, erectile dysfunction, or skin rash. Although these side effects can be disruptive and frustrating, studies have suggested that they typically resolve once the drug is stopped or after continued longer-term use.

Whether you take medications for male-pattern hair loss is a decision that can be made between you and your healthcare provider. It is also OK to accept your hair loss and forgo treatment if that is best for you. If hair loss negatively affects your mental health, talk to your healthcare provider about available options. In addition to medication, reaching out to support groups or working with a therapist could be beneficial.

Tell your healthcare provider about any health conditions and any prescription drugs, OTC medications, vitamins, or herbal supplements you take.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Propecia label.

  2. Food and Drug Administration. Proscar label.

  3. MedlinePlus. Finasteride.

  4. Mysore V, Shashikumar BM. Guidelines on the use of finasteride in androgenetic alopecia. Indian J Dermatol Venereol Leprol. 2016;82(2):128-134. doi:10.4103/0378-6323.177432

  5. Goldstein BG, Goldstein AO. Patient education: androgenetic alopecia in men and women (beyond the basics). UpToDate.

By Kaylea Swearingen, PharmD
Kaylea Swearingen is a registered pharmacist and health and wellness writer.