Finasteride FDA Approval History: Dates, Labels, and Safety Updates

When was finasteride first approved?

Finasteride reached the U.S. market as Proscar 5 mg. Drugs@FDA records the original approval as June 19, 1992, submission type 1 (new molecular entity) under priority review, NDA 020180, with Organon as the current holder [2]. Proscar is indicated to improve symptoms of benign prostatic hyperplasia in men with an enlarged prostate, to reduce the risk of acute urinary retention, and to reduce the risk of surgery including transurethral resection of the prostate and prostatectomy [2]. The label carries an explicit limitation of use: Proscar is not approved for the prevention of prostate cancer [2].

When was Propecia approved?

Propecia 1 mg was approved December 19, 1997, as submission type 3 (new dosage form), NDA 020788, also held now by Organon [1]. The labeled indication is male pattern hair loss (androgenetic alopecia) in men only; efficacy in bitemporal recession has not been established and the drug is not indicated for use in women [5]. The dose is one 1 mg tablet once daily, with or without meals [5].

What did the 1998 hair-count trial show?

Kaufman and colleagues published the hair-loss results in the Journal of the American Academy of Dermatology in 1998. The work comprised two 1-year placebo-controlled trials in 1,553 men aged 18 to 41, and 1,215 men continued into blinded extension studies for a second year [6]. Hair count was measured in a 1-inch diameter circular area (5.1 cm2) of balding vertex scalp, with a baseline of 876 hairs. Finasteride 1 mg produced 107 more hairs than placebo at 1 year and 138 more at 2 years (P<0.001 for both), while the placebo group continued to lose hair [6].

Which forms of finasteride are FDA-approved?

Drugs@FDA lists finasteride only as oral tablets: Propecia 1 mg and Proscar 5 mg [1][2]. No topical or injectable finasteride is FDA-approved.

The 2011 high-grade prostate cancer warning

Drugs@FDA lists labeling supplements dated June 9, 2011 for both products (S-22 for Propecia, S-39 for Proscar) [1][2]. The warning rests on the 7-year Prostate Cancer Prevention Trial, which randomized 18,882 men aged 55 or older to finasteride 5 mg daily or placebo: Gleason score 8 to 10 cancer occurred in 1.8% of men on finasteride versus 1.1% on placebo [4][7].

The same trial found prostate cancer overall in 18.4% of men on finasteride (803 of 4,368 with final-analysis data) versus 24.4% on placebo (1,147 of 4,692), a 24.8% relative reduction (95% CI 18.6 to 30.6) [7]. The Proscar label states that 5-alpha reductase inhibitors may increase the risk of high-grade prostate cancer, and that whether the drugs' reduction of prostate volume or study-related factors affected these results has not been established [4]. A similar pattern appeared with dutasteride in a 4-year trial (1% versus 0.5% placebo) [4].

Propecia's label carries the same high-grade cancer warning in its Warnings and Precautions section, and states that the clinical significance of the finding for men using the 1 mg dose is unknown [5].

What do the current labels say about sexual side effects?

The current Propecia postmarketing section lists sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, libido disorders, ejaculation disorders and orgasm disorders, plus male infertility and poor seminal quality [5]. Proscar's label says such persistent events were reported rarely in men taking 5 mg for BPH, that most of those men were older and taking other medicines, and that the independent role of the drug is unknown [4].

The controlled-trial numbers in the Propecia label were collected over 12 months in 945 men on finasteride and 934 on placebo: decreased libido 1.8% versus 1.3%, erectile dysfunction 1.3% versus 0.7%, and ejaculation disorder 1.2% versus 0.7% [5]. Overall, 36 of 945 men (3.8%) on finasteride reported one or more of these versus 20 of 934 (2.1%) on placebo (p=0.04), and discontinuation for drug-related sexual events was 1.2% versus 0.9% [5]. Resolution occurred in men who discontinued finasteride because of these effects and in most of those who continued, and the incidence of each fell to 0.3% or lower by year five [5]. A self-administered sexual function questionnaire at month 12 showed differences favoring placebo in 3 of 4 domains: sexual interest, erections and perception of sexual problems [5].

The 2022 safety labeling change order

On May 31, 2022, FDA sent a Safety Labeling Change order under section 505(o)(4) of the FD&C Act, citing new safety information on the risk of suicidal ideation and behavior and additional risk of sexual dysfunction and psychoneurocognitive adverse events [3]. Before that order, the Propecia label of June 2021 listed postmarketing 'Nervous System/Psychiatric: depression' [3]. Supplement S-030, approved August 1, 2022, changed the wording to 'depression, suicidal ideation and behavior' [3].

The current Propecia and Proscar labels list depression and suicidal ideation as postmarketing reports. The labels state the reports are voluntary, come from a population of uncertain size, and that a causal relationship cannot reliably be established [5][4].

Do the current labels carry a boxed warning?

Current Propecia and Proscar labels do not carry boxed warnings, and depression and suicidal ideation sit in the Postmarketing Experience section rather than in a numbered Warnings and Precautions subsection [5][3].

Observational data on the psychiatric question are mixed. A matched cohort of 93,197 Ontario men aged 66 or older starting a 5-alpha reductase inhibitor, mostly for BPH, found no increase in suicide (hazard ratio 0.88, 95% CI 0.53 to 1.45), a higher risk of self-harm confined to the first 18 months (HR 1.88, 1.34 to 2.64), and higher rates of depression in the first 18 months (HR 1.94, 1.73 to 2.16) and afterward (HR 1.22, 1.08 to 1.37) [8]. A Swedish register study of 2,236,876 men aged 50 to 90, including 70,645 who started finasteride at a median age of 73, found depression HR 1.61 (1.48 to 1.75) with no significant suicide association (HR 1.22, 0.99 to 1.49) [9]. Both studies examined mainly older men treated for prostate enlargement rather than young men taking 1 mg for hair loss [8][9].

Pregnancy

Pregnancy is a contraindication on both labels [5][4]. The Propecia label warns that women who are pregnant or may become pregnant should not handle crushed or broken tablets, because finasteride can be absorbed and may cause abnormalities of the external genitalia of a male fetus [5]. According to the label, the tablets are coated and prevent contact with the active ingredient during normal handling as long as they are not broken or crushed, and if a pregnant woman contacts a crushed or broken tablet, the contact area should be washed immediately with soap and water [5]. Finasteride is not indicated for use in women [5].

Regulatory timeline

• June 19, 1992: Proscar 5 mg approved, NDA 020180, priority review [2]
• December 19, 1997: Propecia 1 mg approved, NDA 020788, new dosage form [1]
• 1998: Kaufman et al. publish the 1-year and 2-year hair count results [6]
• April 10, 2002: Propecia labeling supplement S-7, an efficacy labeling change with clinical data [1]
• June 9, 2011: labeling supplements approved for both products, adding the high-grade prostate cancer warning [1][2]
• May 31, 2022: FDA safety labeling change order on suicidal ideation and behavior [3]
• August 1, 2022: Propecia supplement S-030 approved with the revised psychiatric wording [1][3]
• March 18, 2026: Proscar supplement S-050, the current 5 mg label [2]