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.
What Is Finasteride Used For?
The Food and Drug Administration (FDA) has approved finasteride to treat:
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
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 urinatingDecreased flow of urinationHesitation at the beginning of urinationA 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.
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.
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.
Common Side Effects
The most common side effects of finasteride include:
Decreased sex drive Ejaculation dysfunction Erectile dysfunction (trouble getting or keeping an erection)
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:
Swelling of the tongue, lips, or mouth Lumps or pain in the breast Depression Nipple discharge
Contact your healthcare provider if you experience any of the above-listed side effects.
Dosage: How Much Finasteride Should I Take?
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.
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).
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.
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.
Precautions
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.
If someone collapses or isn’t breathing after taking finasteride, call 911 immediately.
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.
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:
Liver disease Prostate cancer
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:
Rogaine (minoxidil) Aldactone (spironolactone) Avodart (dutasteride)
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:
Alpha-blockers, such as Flomax (tamsulosin), Uroxatral (alfuzosin), and Rapaflo (silodosin) Cialis (tadalafil), a phosphodiesterase inhibitor
Talk to your healthcare provider about what might be the best option for you.
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.
