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Terms Of Use


Brand Name(s) : Proscar, Propecia
Side Effects


Finasteride should be used with caution in: patients who are about to have a blood test for prostate-specific antigen (PSA).

It should not be used in: women, children or adolescents.

Also see list of precautions and interactions.


Store below 30°C.


What is it used for?

  • Finasteride is used to treat benign prostatic hyperplasia (BPH) which can cause problems with urination (passing water).
  • It is a specific inhibitor of the enzyme 5-alpha-reductase, which metabolises testosterone and leads to a reduction in the size of the prostate gland, sometimes called an alpha blocker or an alpha-1 blocker.
  • It is used to inhibit the enzyme 5-alpha-reductase, which normally metabolises testosterone to produce dihydrotestosterone. One effect of this inhibition is to reduce the size of the prostate gland, and this in turn can relieve the symptoms of benign prostatic hyperplasia such as difficulties in urination.
  • In general this drug is used to treat the symptoms of benign prostatic hypertrophy, but also to increase hair growth and prevent further hair loss in a certain type of baldness in men (male pattern baldness) that occurs because of the androgen dihydrotestosterone.
  • Benefits of being on this drug can include an increase in urine flow rate and improvement in some of the symptoms of urine-flow obstruction.

Listed below are the typical uses of finasteride.

On occasion your doctor may prescribe this medicine to treat a condition not on the above list.


How often do I take it?

  • Take this medication by mouth, usually once daily, with or without food.
  • Use this medication regularly in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told otherwise by your doctor.
  • It may take some time before the full benefit of this drug takes effect.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • Avoid sex without a condom if your partner is pregnant or of child-bearing age. Crushed tablets should not be handled by women who are pregnant or planning to become pregnant. Consult your doctor or pharmacist for more details.

When can I stop?

  • It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop.


  • Decreased sex drive
  • Impotence
  • Ejaculation disorders (e.g. decreased volume of semen released during sex)
  • Enlarged or tender breast areas
  • Rash
  • Pain in the testicles.
This is not a complete list of possible side effects. If any of these persist or you consider them severe then inform doctor or pharmacist.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.


Before taking finasteride, tell your doctor or pharmacist if you are allergic to it; or to other 5-alpha-reductase inhibitors; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you are: women, children or adolescents.

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: having a blood test for prostate-specific antigen (PSA).

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • It is not known whether drinking alcohol affects this drug's action.

The elderly: finasteride can be used in the elderly.

Pregnancy and breastfeeding - please ensure you read the detailed information below


Not applicable (only used in men).


Not applicable (only used in men).


Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

This drug should not be used with the following medications because very serious, possibly fatal interactions may occur: none known.

Before using this medication, tell your doctor or pharmacist of all prescription and non-prescription/herbal products you may use, especially of: none known.

This information does not contain all possible interactions. Therefore, before using finasteride, tell your doctor or pharmacist of all the products you use.


Serious adverse effects are unlikely to occur with an overdose.

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of finasteride or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.


If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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