Who Cannot Take Finasteride? A Comprehensive Guide to Contraindications

October 7, 2025 •

4 min read

According to Mayo Clinic, finasteride is prescribed to men for benign prostatic hyperplasia (BPH) and male pattern hair loss, but it is not for everyone and can be very dangerous for certain populations. Understanding who cannot take finasteride is critical for patient safety, as improper use can lead to serious health complications, including birth defects.

Quick Summary

A guide to individuals who must avoid finasteride, including women, children, and those with specific health issues. Important risks and precautions are detailed to ensure safe medication use.

Key Points

Pregnant Women: Absolutely cannot take or handle crushed finasteride tablets due to a significant risk of severe birth defects in male fetuses.
Children and Adolescents: Not approved for use in pediatric populations, as its hormonal effects can interfere with normal growth and sexual development.
Allergic Reactions: Individuals with known hypersensitivity to finasteride or its components should not take the medication to avoid potentially severe allergic reactions.
Liver Disease: Patients with liver function abnormalities should use finasteride with caution, as liver impairment can lead to a dangerous buildup of the drug in the body.
Mental Health Conditions: Those with a history of depression or low mood should be cautious, as finasteride has been linked to mental health side effects in some users.
Risk of High-Grade Prostate Cancer: Finasteride can increase the risk of high-grade prostate cancer in some men, a risk that should be discussed with a doctor.

Understanding Finasteride and Its Uses

Finasteride is a medication that belongs to a class of drugs known as 5-alpha reductase inhibitors. Its primary mechanism involves blocking the conversion of testosterone into dihydrotestosterone (DHT), a potent androgen responsible for prostate growth and androgenetic alopecia (male pattern baldness). By lowering DHT levels, finasteride can shrink an enlarged prostate in men with Benign Prostatic Hyperplasia (BPH) and slow or reverse hair loss. While effective for many, its hormonal action means it is not suitable for everyone and has a number of critical contraindications.

Primary Contraindications for Finasteride

Women Who Are Pregnant or May Become Pregnant

This is the most critical contraindication for finasteride. The drug is classified as Pregnancy Category X, meaning it is known to cause birth defects and is strictly forbidden during pregnancy. Finasteride can be absorbed through the skin, so pregnant women or those who may become pregnant should not handle crushed or broken tablets. Exposure can interfere with the development of a male fetus's external genitalia, causing abnormalities. If contact with a damaged tablet occurs, the area should be washed immediately with soap and water. Even after a man has discontinued the medication, the drug can remain in the body for an extended period, so handling precautions are necessary for partners who are pregnant.

Pediatric Patients

Finasteride is not indicated for use in children. Its effects on hormonal balance can interfere with normal growth and sexual development in adolescents and prepubescent children, and its safety and efficacy in this population have not been established.

Individuals with Hypersensitivity or Allergic Reactions

Anyone with a known hypersensitivity or allergic reaction to finasteride or any of its components should not take the medication. Symptoms of an allergic reaction can include rash, itching, hives, swelling of the lips, face, or tongue, and difficulty breathing. A severe allergic reaction requires immediate medical attention.

Medical Conditions Requiring Caution or Avoidance

Liver Disease

Finasteride is extensively metabolized by the liver, so patients with liver disease or significant liver function abnormalities must be cautious. Impaired liver function can slow the removal of the drug from the body, potentially leading to a buildup that increases the risk of side effects. Your doctor may need to adjust the dose or recommend an alternative treatment.

Obstructive Uropathy or Severe Bladder Problems

Men with a large residual urinary volume or significantly diminished urinary flow should be monitored carefully before starting finasteride. Finasteride works by shrinking the prostate over time, but in cases of severe blockage, it may not be sufficient to relieve the obstruction. Alternative treatments might be necessary for patients with these conditions.

Depression or Mental Health Issues

While rare, some individuals have reported experiencing depression, low mood, or anxiety while taking finasteride. The link between finasteride and these mental health side effects is still under investigation, but those with a history of depression or suicidal ideation should discuss the risks with their doctor. If you experience these side effects, especially when taking it for hair loss, the NHS recommends stopping the medication and contacting your doctor immediately.

High-Grade Prostate Cancer

Studies like the Prostate Cancer Prevention Trial have shown that while finasteride can reduce the overall risk of prostate cancer, it can increase the risk of developing a high-grade form of the disease. This serious consideration requires a thorough discussion with a doctor, especially for men over 55. Finasteride can also significantly lower Prostate-Specific Antigen (PSA) levels, a common marker for prostate cancer. This can mask the presence of cancer, so doctors must adjust the interpretation of PSA test results for patients on finasteride.

Comparison of Patient Considerations for Finasteride Use


Patient Group	Risk/Consideration	Action
Pregnant Women	Severe birth defects in male fetuses.	Strictly contraindicated. Avoid handling crushed or broken tablets.
Children/Adolescents	Interference with growth and sexual development.	Not indicated for use. Safety not established.
Men with Liver Disease	Slower drug metabolism, potential for increased side effects.	Use with caution. Dosage may be adjusted by a doctor.
Men with Depression	Potential link to low mood, depression, and anxiety.	Use with caution. Consult a doctor immediately if symptoms occur.
Men with Severe BPH	May not relieve severe urinary obstruction.	Monitor for obstructive uropathy. Alternative treatments may be needed.
Men with Prostate Cancer Risk	Masked PSA levels and increased risk of high-grade cancer.	Discuss risks with a doctor. Require adjusted interpretation of PSA tests.

Alternatives to Finasteride

For those who cannot take finasteride, several alternatives are available for treating hair loss and BPH. Minoxidil is a common over-the-counter treatment for hair loss that can be used by both men and women. It works by increasing blood flow to the hair follicles and does not affect hormones like finasteride does. For BPH, other medications or procedures may be more appropriate depending on the severity of the condition and overall health. Always consult with a healthcare professional to determine the best alternative for your specific situation.

Conclusion

While finasteride can be an effective treatment for male pattern baldness and BPH, it is not a suitable option for everyone due to significant contraindications and potential risks. The most critical warnings apply to pregnant women and children, but caution is also necessary for those with pre-existing liver disease, bladder problems, or a history of depression. Due to its effects on PSA levels and the potential for high-grade prostate cancer, men should have a thorough discussion with their doctor before starting treatment. Ultimately, a proper medical evaluation is essential to determine whether finasteride is safe for you and to explore alternatives if necessary. For more information, please consult the US Food and Drug Administration guidelines.

Frequently Asked Questions

Finasteride is contraindicated for women who are or may become pregnant because it can cause severe birth defects in a male fetus by affecting genital development. Furthermore, its effectiveness for female pattern hair loss is limited, and other hormonal effects can occur.

While sometimes used off-label in postmenopausal women with specific supervision, finasteride is generally not recommended for women of childbearing age due to the high risk associated with unplanned pregnancy. Alternative treatments like minoxidil are often safer and more effective for women.

If a pregnant woman comes into contact with crushed or broken finasteride tablets, she should immediately wash the affected area with soap and water and contact her doctor. The medication can be absorbed through the skin.

Yes, finasteride can reduce serum PSA (Prostate-Specific Antigen) levels by approximately 50%, which can mask the detection of prostate cancer. It is important to inform your doctor that you are taking finasteride so they can adjust the interpretation of your PSA results.

Men with a history of depression or low mood should discuss the risks with their doctor before starting finasteride. Some patients have reported mood changes, and if such side effects occur, especially when treating hair loss, a doctor may recommend discontinuing the medication.

Yes, a common alternative is minoxidil (Rogaine), a topical treatment available over-the-counter for both men and women. Other non-medical alternatives, such as gentle hair care and nutritional support, can also be considered.

If you experience any serious side effects like lumps, pain, or swelling in your chest, or severe allergic reactions, contact your doctor immediately. These could indicate a serious condition such as breast cancer.