Finasteride

Short answer

Finasteride is FDA-approved as a pill for an enlarged prostate (Proscar) and for male hair loss (Propecia). For both uses the evidence grade is strong-human. It can harm a male fetus, and lasting sexual problems and depression have been reported. No topical form is FDA-approved.

Our assessment, drawn from the sources below.

What it is

Where it stands legally

What the evidence shows

Evidence grade: strong-human · our assessment

Known risks

• It can cause abnormal genitals in a male fetus. Women who are or may be pregnant must not take it or handle crushed or broken tablets ^{[1] [2]}.
• Topical forms have no coating, so the drug can pass to a woman by touch. FDA says this raises the risk to a pregnancy ^[6].
• Sexual problems are the most common harm. In the 4-year Proscar study, 8.1% on it had impotence in year one, against 3.7% on a dummy pill ^[1].
• Sexual problems that went on after stopping have been reported. They include erection, sex drive and ejaculation problems ^{[1] [2]}.
• Depression and thoughts of suicide have been reported in people on it. The Propecia label also lists suicidal acts ^{[1] [2]}.
• In a 7-year trial, high-grade prostate cancer was found in 1.8% of men on it and 1.1% on a dummy pill ^{[1] [12]}.
• It lowers the PSA blood test for prostate cancer by about half. Any confirmed rise in PSA while on it should be checked ^{[1] [2]}.
• Breast growth and tenderness, and male breast cancer, have been reported ^{[1] [2]}.
• Male infertility and poor semen quality have been reported. In some men it improved after stopping ^{[1] [2]}.
• Allergic reactions have been reported, including swelling of the lips, tongue, throat and face ^{[1] [2]}.
• Testicular pain and blood in the semen have been reported ^{[1] [2]}.
• It is not for children or women ^{[1] [2]}.
• From 2019 to 2024, FDA got 32 reports of harm tied to compounded topical finasteride. Most said the problems went on after stopping ^[6].
• In 2020, some compounded hair loss capsules were recalled. Tests found minoxidil in them, and the label did not list it ^[7].

What nobody knows yet

• Nobody knows if finasteride itself causes sexual problems that last after stopping. The Proscar label says its role is unknown ^[1].
• The labels say the link between long-term use and male breast cancer is unknown ^{[1] [2]}.
• It is not settled whether the drug or the way the study was run caused the higher rate of high-grade prostate cancer ^[1].
• A 2021 study of a global safety database found more suicide-related reports in people under 45 who took it for hair loss. The authors said this may come from how reports were made, or from younger people being more at risk ^[17].
• Nobody knows if a topical form is lower risk over years. The 2022 spray trial lasted 24 weeks ^[15].
• A 2019 rat study found lasting depression-like behavior after the drug was stopped. Nobody has shown the same cause in people ^[18].
• A patient group told FDA in 2023 that some men stay unwell after stopping. The group said how it happens is unclear and there is no treatment ^[20].

Legitimate ways to get it

• Approved product

  Approved by FDA as a prescription tablet taken by mouth once a day for an enlarged prostate, alone or with doxazosin.

  Brand names: Proscar

  Manufacturer: Organon

  Indication: Symptoms of an enlarged prostate (benign prostatic hyperplasia), and lower risk of urine retention and surgery.

  accessdata.fda.gov

• Approved product

  Approved by FDA as a prescription tablet taken by mouth once a day for male pattern hair loss, in men only.

  Brand names: Propecia

  Manufacturer: Organon

  Indication: Male pattern hair loss (androgenetic alopecia) in men only.

  accessdata.fda.gov

• Lawful compounding

  Pharmacies may compound with a raw substance that meets a USP standard or is part of an FDA-approved drug. No topical form is FDA-approved.

  fda.gov

How people are getting it anyway

This section describes what happens and is not a recommendation.

• Telehealth

  Online prescribers that sell compounded topical finasteride for hair loss, alone or mixed with minoxidil.

  The lawFDA says no topical finasteride is FDA-approved, and compounded topical products have no FDA-approved label.fda.gov

  Documented riskFDA got 32 reports of harm tied to compounded topical finasteride from 2019 to 2024, and most said the problems went on after stopping.fda.gov

  Documented riskFDA warns a topical form can pass by touch to a woman and harm a male fetus.fda.gov

  Documented riskCompounded finasteride capsules for hair loss were recalled after testing found minoxidil not listed on the label.fda.gov

  Enforcement 2025-04-22FDA alerted prescribers, compounders and consumers to reports of harm tied to compounded topical finasteride.fda.gov

Sources

1. [1]Proscar (finasteride) tablets label, revised March 2026Label · primary
2. [2]Propecia (finasteride) tablets label, revised July 2022Label · primary
3. [3]Drugs@FDA: Proscar (finasteride) tablets, application 020180Regulatory · primary
4. [4]Drugs@FDA: Propecia (finasteride) tablets, application 020788Regulatory · primary
5. [5]Drugs@FDA: Entadfi (finasteride and tadalafil) capsules, application 215423Regulatory · primary
6. [6]FDA alert: potential risks of compounded topical finasteride products, April 2025Regulatory · primary
7. [7]FDA-posted recall notice: compounded finasteride capsules with undeclared minoxidil, May 2020Regulatory · primary
8. [8]FDA: bulk drug substances used in compounding under section 503ARegulatory · primary
9. [9]FDA: 503A bulk drug substances category listRegulatory · primary
10. [10]FDA: bulk drug substances that may present significant safety risks (Category 2)Regulatory · primary
11. [11]FDA: understanding the risks of compounded drugsRegulatory · primary
12. [12]Prostate Cancer Prevention Trial: finasteride and prostate cancer, 2003Rct · peer-reviewed
13. [13]Randomized trial: doxazosin, finasteride or both for an enlarged prostate getting worse, 2003Rct · peer-reviewed
14. [14]Randomized trials: finasteride in men with male pattern hair loss, 1998Rct · peer-reviewed
15. [15]Randomized trial in Europe: topical finasteride spray for male hair loss, 2022Rct · peer-reviewed
16. [16]Systematic review: finasteride for male pattern hair loss, 2010Systematic review · peer-reviewed
17. [17]Global safety database study: suicidal thoughts and mood problems reported with finasteride, 2021Human trial · peer-reviewed
18. [18]Rat study: finasteride and lasting depression-like behavior, 2019Animal · peer-reviewed
19. [19]ClinicalTrials.gov NCT04288427: 5-alpha reductase 2 as a marker of resistance to finasteride in an enlarged prostateReference · primary
20. [20]FDA patient listening session on post-finasteride syndrome, report by a patient group, June 2023Reference · primary
21. [21]UPI: FDA warns of risks of compounded topical finasteride sold online, April 2025Reference · established-news