Skip to Content
Looking to save on your medications?  Find out how 

Proscar

Generic name: finasteride

What is Proscar?

Proscar is for use by men only.

Proscar is a medication used to treat symptoms of benign prostatic hyperplasia (BPH) in men with an enlarged prostate. Proscar may also be used to reduce the risk of a sudden inability to pass urine and the need for surgery related to BPH in men with an enlarged prostate.

Proscar may be prescribed along with another medicine, an alpha-blocker called doxazosin, to help you better manage your BPH symptoms.

What is BPH?

BPH is an enlargement of the prostate gland. The prostate is located below the bladder. As the prostate enlarges, it may slowly restrict the flow of urine. This can lead to symptoms such as:

  • a weak or interrupted urinary stream
  • a feeling that you cannot empty your bladder completely
  • a feeling of delay or hesitation when you start to urinate
  • a need to urinate often, especially at night
  • a feeling that you must urinate right away.

In some men, BPH can lead to serious problems, including urinary tract infections, a sudden inability to pass urine (acute urinary retention), as well as the need for surgery.

What Proscar does:

Proscar lowers levels of a hormone called DHT (dihydrotestosterone), which is a cause of prostate growth. Lowering DHT leads to shrinkage of the enlarged prostate gland in most men. This can lead to gradual improvement in urine flow and symptoms over the next several months. Proscar will help reduce the risk of developing a sudden inability to pass urine and the need for surgery related to an enlarged prostate. However, since each case of BPH is different, you should know that:

  • Even though the prostate shrinks, you may not notice an improvement in urine flow or symptoms.
  • You may need to take Proscar for six (6) months or more to see whether it improves your symptoms.
  • Therapy with Proscar may reduce your risk for a sudden inability to pass urine and the need for surgery for an enlarged prostate.

Who should not take Proscar?

Proscar is for use by men only.

Do not take Proscar if you are:

  • a woman who is pregnant or may potentially be pregnant. Proscar may harm your unborn baby. Do not touch or handle crushed or broken Proscar tablets (see "A warning about Proscar and pregnancy" below).
  • allergic to finasteride or any of the ingredients in Proscar. See the end of this leaflet for a complete list of ingredients in Proscar.

A warning about Proscar and pregnancy:

Women who are or may potentially be pregnant must not use Proscar. They should also not handle crushed or broken tablets of Proscar. Proscar tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets are not broken or crushed.

If a woman who is pregnant with a male baby absorbs the active ingredient in Proscar after oral use or through the skin, it may cause the male baby to be born with abnormalities of the sex organs. If a woman who is pregnant comes into contact with the active ingredient in Proscar, a doctor should be consulted.

How should I take Proscar?

Follow your doctor's instruction.

  • Take one tablet by mouth each day. To avoid forgetting to take Proscar, you can take it at the same time every day.
  • If you forget to take Proscar, do not take an extra tablet. Just take the next tablet as usual.
  • You may take Proscar with or without food.
  • Do not share Proscar with anyone else; it was prescribed only for you.

What you need to know while taking Proscar:

  • You should see your doctor regularly while taking Proscar. Follow your doctor's advice about when to have these checkups.
  • Checking for prostate cancer. Your doctor has prescribed Proscar for BPH and not for treatment of prostate cancer — but a man can have BPH and prostate cancer at the same time. Your doctor may continue checking for prostate cancer while you take Proscar.
  • About Prostate-Specific Antigen (PSA). Your doctor may have done a blood test called PSA for the screening of prostate cancer. Because Proscar decreases PSA levels, you should tell your doctor(s) that you are taking Proscar. Changes in PSA levels will need to be evaluated by your doctor(s). Any increase in follow-up PSA levels from their lowest point may signal the presence of prostate cancer and should be evaluated, even if the test results are still within the normal range. You should also tell your doctor if you have not been taking Proscar as prescribed because this may affect the PSA test results. For more information, talk to your doctor.

What are the possible side effects of Proscar?

Proscar may increase the chance of a more serious form of prostate cancer.

The most common side effects of Proscar include:

  • trouble getting or keeping an erection (impotence)
  • decrease in sex drive
  • decreased volume of ejaculate
  • ejaculation disorders
  • enlarged or painful breast. You should promptly report to your doctor any changes in your breasts such as lumps, pain or nipple discharge.

The following have been reported in general use with Proscar and/or finasteride at lower doses:

  • allergic reactions, including rash, itching, hives, and swelling of the lips, tongue, throat, and face
  • rarely, some men may have testicular pain
  • trouble getting or keeping an erection that continued after stopping the medication
  • problems with ejaculation that continued after stopping the medication
  • male infertility and/or poor quality of semen. Improvement in the quality of semen has been reported after stopping the medication.
  • depression
  • decrease in sex drive that continued after stopping the medication
  • in rare cases, male breast cancer has been reported.

You should discuss side effects with your doctor before taking Proscar and anytime you think you are having a side effect. These are not all the possible side effects with Proscar. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at: 1-800-FDA-1088.

Proscar Images

General information about the safe and effective use of Proscar

Do not give your Proscar tablets to anyone else. It has been prescribed only for you.

For more information call 1-800-622-4477.

How should I store Proscar?

  • Store Proscar tablets in a dry place at room temperature.
  • Keep Proscar in the original container and keep the container closed.
  • Proscar tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets are not broken or crushed.

Keep Proscar and all medications out of the reach of children.

What are the ingredients in Proscar?

Active ingredients: finasteride

Inactive ingredients: hydrous lactose, microcrystalline cellulose, pregelatinized starch, sodium starch glycolate, hydroxypropyl cellulose LF, hydroxypropyl methylcellulose, titanium dioxide, magnesium stearate, talc, docusate sodium, FD&C Blue 2 aluminum lake and yellow iron oxide.

Source: National Library of Medicine. Last updated November 15, 2019.