Uses
What is finasteride used for?
Finasteride is commonly used for the following conditions.
- Androgenic alopecia (gradual thinning or loss of hair on the scalp in men)
- Benign prostatic hyperplasia (symptoms of an enlarged prostate without prostate cancer)
Finasteride may also be used for other conditions as determined by your healthcare provider.
How does finasteride work (mechanism of action)?
Dihydrotestosterone (DHT) is a hormone that makes the prostate gland grow larger than usual and leads to hair loss on the scalp. Finasteride works by blocking an enzyme that turns testosterone into DHT. This helps reduce the size of the prostate, which makes it easier to pee. It also slows down hair loss in men.
How is finasteride supplied (dosage forms)?
Brands and other names
- Propecia
- Proscar
Dosage forms and strengths
- 1 mg oral tablets (Propecia)
- 5 mg oral tablets (Proscar)
How should I store finasteride?
Finasteride should be stored at room temperature, between 59 to 86 F (15 C to 30 C). Store in a cool and dry place in a tightly closed container. Protect it from moisture. Some finasteride tablets should be stored in the original container to protect from light. Check with your pharmacist if you have questions about storing finasteride.
Side Effects
What are the most common side effects of finasteride?
The most common side effects of finasteride are listed below. Tell your healthcare provider if you have any of these side effects that bother you.
- Reduced sex drive
- Problems getting or keeping an erection
- Problems with ejaculation
- Sore or enlarged breasts in men
- Rash
There may be other side effects of finasteride that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of finasteride?
While less common, the most serious side effects of finasteride are described below, along with what to do if they happen.
Severe Allergic Reactions. Finasteride can cause allergic reactions, which can be serious. Stop using finasteride and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble in swallowing or throat tightness
- Itching, skin rash, or pale red bumps on the skin called hives
- Nausea or vomiting
- Dizziness, feeling lightheaded or fainting
- Stomach cramps
- Joint pain
Suicidal Thoughts. Finasteride may cause depression and suicidal thoughts in a small number of people.
If you are about to harm yourself, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you have any of the following symptoms.
- New or increased thoughts of suicide or death
- Suicide attempt
- New or increased feelings of anxiety, depression, or other unusual changes in mood or behavior
Risk of Prostate Cancer. While rare, finasteride may raise the risk of a serious form of prostate cancer that can spread quickly. Prostate cancer and benign prostatic hyperplasia (BPH) may cause similar symptoms, such as urination (peeing) problems. Finasteride is commonly used to treat BPH, which is non-cancerous enlargement of the prostate. In some people, BPH can occur at the same time as prostate cancer. Get prostate cancer screening tests as recommended by your healthcare provider. Tell all of your healthcare providers that you are taking finasteride. And, tell your healthcare provider right away if you have any of the following symptoms, especially if they are more frequent or severe than usual.
- Difficult, frequent, or painful urination
- Bloody pee or semen
- Pain in your back, pelvis, or hips that does not go away
- Weight loss for no clear reason
Warnings & Precautions
Who should not use finasteride?
Allergies to Ingredients. People who are allergic to any of the following should not take finasteride products.
- Finasteride
- Propecia
- Proscar
- Any of the ingredients in the specific product dispensed
Your pharmacist can tell you all of the ingredients in the specific finasteride products they stock.
Pregnancy. Finasteride is not for use in women. See the Pregnancy section for more details.
What should I know about finasteride before using it?
Do not take finasteride unless it has been prescribed to you by a healthcare provider. Take it as prescribed.
Do not share finasteride with other people, even if they have the same condition as you. It may harm them.
Keep finasteride out of the reach of children.
It may take several months of taking finasteride before you notice any improvement in symptoms. Talk to your healthcare provider if you have concerns about how well finasteride is working.
Finasteride may affect semen. You may have less semen than usual, and the number and activity of sperm may be reduced. These changes may continue after finasteride is stopped. It is unknown if these changes could affect your fertility (the ability to father a baby). If you have any concerns or questions about this, talk to your healthcare provider before starting finasteride.
People who are or may be pregnant should not touch broken or crushed finasteride tablets. Finasteride can be absorbed through the skin and may harm an unborn baby. If skin contact occurs, wash the area right away with soap and water.
Finasteride can lower the levels of prostate-specific antigen (PSA) in your blood. You should still get PSA tests to check for prostate cancer as advised by your healthcare provider. Finasteride does not help prevent prostate cancer.
Tell your healthcare provider right away if you get any breast pain, breast lumps, or nipple discharge. Breast cancer in men has rarely been reported.
What should I tell my healthcare provider before using finasteride?
Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if finasteride is right for you.
Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.
- Liver problems
- Prostate problems
- Bladder problems
Pregnancy. Do not take finasteride, and tell your healthcare provider if you are or plan to become pregnant. Finasteride may cause harm to an unborn baby if the medicine is taken or broken or crushed tablets are touched by someone who is pregnant.
Breastfeeding. People who can breastfeed are not usually prescribed finasteride. It is not known if finasteride passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed.
Interactions
Does finasteride interact with foods or drinks?
There are no known interactions between finasteride and foods or drinks.
It is unknown if drinking alcohol will affect finasteride.
Does finasteride interact with other medicines (drug interactions)?
There are no known interactions between finasteride and other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
Overdose/Missed Dose
What should I do if I accidentally use too much finasteride?
If you or someone else has taken too much finasteride, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
What should I do if I miss a dose of finasteride?
If you miss a dose, skip the missed dose. Take your next dose when you normally would. Do not take double or extra doses.
Are you currently using Finasteride?
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