Finasteride
Generic name: finasteride · Brand names: Finasteride
5-Alpha Reductase Inhibitor [epc]Information sourced from FDA Structured Product Labeling, updated June 10, 2026.
What is it used for?
Finasteride tablets is indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY . Efficacy in bitemporal recession has not been established. Finasteride tablets is not indicated for use in women. Finasteride tablets is a 5α-reductase inhibitor indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY. Finasteride tablets is not indicated for use in women ( 1 , 4 , 5.1 ).
How to take it
Finasteride tablets may be administered with or without meals. The recommended dose of finasteride tablets, USP 1 mg is one tablet (1 mg) taken once daily. In general, daily use for three months or more is necessary before benefit is observed. Continued use is recommended to sustain benefit, which should be re-evaluated periodically.
Withdrawal of treatment leads to reversal of effect within 12 months. Finasteride tablets may be administered with or without meals. One tablet ( 1 mg ) taken once daily. In general, daily use for three months or more is necessary before benefit is observed.
Warnings
Finasteride tablets is not indicated for use in women or pediatric patients ( 5.1 , 5.4 ). Women should not handle crushed or broken finasteride tablets when they are pregnant or may potentially be pregnant due to potential risk to a male fetus ( 5.1 , 8.1 , 16 ). Finasteride tablets causes a decrease in serum PSA levels. Any confirmed increase in PSA while on finasteride tablets may signal the presence of prostate cancer and should be evaluated, even if those values are still within the normal range for men not taking a 5α-reductase inhibitor. 5α-reductase inhibitors may increase the risk of high - grade prostate cancer ( 5.3 , 6.1 ).
Exposure of Women
— Risk to Male Fetus Finasteride tablets is not indicated for use in women. Women should not handle crushed or broken finasteride tablets when they are pregnant or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male fetus. Finasteride tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed.
Effects on Prostate Specific Antigen
(PSA) In clinical studies with finasteride tablets (finasteride, 1 mg) in men 18 to 41 years of age, the mean value of serum prostate specific antigen (PSA) decreased from 0.7 ng/mL at baseline to 0.5 ng/mL at Month 12. Further, in clinical studies with finasteride tablets (finasteride, 5 mg) when used in older men who have benign prostatic hyperplasia (BPH), PSA levels are decreased by approximately 50%. Other studies with finasteride tablets showed it may also cause decreases in serum PSA in the presence of prostate cancer. These findings should be taken into account for proper interpretation of serum PSA when evaluating men treated with finasteride.
Any confirmed increase from the lowest PSA value while on finasteride tablets may signal the presence of prostate cancer and should be evaluated, even if PSA levels are still within the normal range for men not taking a 5α-reductase inhibitor. Non-compliance to therapy with finasteride tablets may also affect PSA test results.
Increased Risk of High-Grade Prostate Cancer
with 5α-Reductase Inhibitors Men aged 55 and over with a normal digital rectal examination and PSA ≤3.0 ng/mL at baseline taking finasteride 5 mg/day (5 times the dose of finasteride tablets) in the 7-year Prostate Cancer Prevention Trial (PCPT) had an increased risk of Gleason score 8 to 10 prostate cancer (finasteride 1.8% vs placebo 1.1%). Similar results were observed in a 4-year placebo-controlled clinical trial with another 5α-reductase inhibitor (dutasteride, AVODART) (1% dutasteride vs 0.5% placebo). 5α- reductase inhibitors may increase the risk of development of high-grade prostate cancer. Whether the effect of 5α-reductase inhibitors to reduce prostate volume, or study-related factors, impacted the results of these studies has not been established.
Pediatric Patients Finasteride
tablets is not indicated for use in pediatric patients .
Who should not take it
Finasteride tablets is contraindicated in the following: Pregnancy. Finasteride use is contraindicated in women when they are or may potentially be pregnant. Because of the ability of Type II 5α-reductase inhibitors to inhibit the conversion of testosterone to 5α-dihydrotestosterone (DHT), finasteride may cause abnormalities of the external genitalia of a male fetus of a pregnant woman who receives finasteride.
If this drug is used during pregnancy, or if pregnancy occurs while taking this drug, the pregnant woman should be apprised of the potential hazard to the male fetus. In female rats, low doses of finasteride administered during pregnancy have produced abnormalities of the external genitalia in male offspring. Hypersensitivity to any component of this medication.
Pregnancy (4 , 5.1 , 8.1 , 16 ). Hypersensitivity to any components of this product.
Pregnancy
Pregnancy Pregnancy Category X
. Finasteride tablets is contraindicated for use in women who are or may become pregnant. Finasteride tablets is a Type II 5α-reductase inhibitor that prevents conversion of testosterone to 5α-dihydrotestosterone (DHT), a hormone necessary for normal development of male genitalia. In animal studies, finasteride caused abnormal development of external genitalia in male fetuses.
If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the male fetus. Abnormal male genital development is an expected consequence when conversion of testosterone to 5α- dihydrotestosterone (DHT) is inhibited by 5α-reductase inhibitors. These outcomes are similar to those reported in male infants with genetic 5α-reductase deficiency.
Women could be exposed to finasteride through contact with crushed or broken finasteride tablets or semen from a male partner taking finasteride tablets. With regard to finasteride exposure through the skin, finasteride tablets are coated and will prevent skin contact with finasteride during normal handling if the tablets have not been crushed or broken. Women who are pregnant or may become pregnant should not handle crushed or broken finasteride tablets because of possible exposure of a male fetus.
If a pregnant woman comes in contact with crushed or broken finasteride tablets, the contact area should be washed immediately with soap and water. With regard to potential finasteride exposure through semen, a study has been conducted in men receiving finasteride tablets 1 mg/day that measured finasteride concentrations in semen . In an embryo-fetal development study, pregnant rats received finasteride during the period of major organogenesis (gestation days 6 to 17). At maternal doses of oral finasteride approximately 1 to 684 times the recommended human dose (RHD) of 1 mg/day (based on AUC at animal doses of 0.1 to 100 mg/kg/day) there was a dose-dependent increase in hypospadias that occurred in 3.6 to 100% of male offspring.
Exposure multiples were estimated using data from nonpregnant rats. Days 16 to 17 of gestation is a critical period in male fetal rats for differentiation of the external genitalia. At oral maternal doses approximately 0.2 times the RHD (based on AUC at animal dose of 0.03 mg/kg/day), male offspring had decreased prostatic and seminal vesicular weights, delayed preputial separation and transient nipple development.
Decreased anogenital distance occurred in male offspring of pregnant rats that received approximately 0.02 times the RHD (based on AUC at animal dose of 0.003 mg/kg/day). No abnormalities were observed in female offspring exposed to any dose of finasteride in utero. No developmental abnormalities were observed in the offspring of untreated females mated with finasteride-treated male rats that received approximately 488 times the RHD (based on AUC at animal dose of 80 mg/kg/day).
Slightly decreased fertility was observed in male offspring after administration of about 20 times the RHD (based on AUC at animal dose of 3 mg/kg/day) to female rats during late gestation and lactation. No effects on fertility were seen in female offspring under these conditions. No evidence of male external genital malformations or other abnormalities were observed in rabbit fetuses exposed to finasteride during the period of major organogenesis (gestation days 6 to 18) at maternal doses up to 100 mg/kg/day (finasteride exposure levels were not measured in rabbits).
However, this study may not have included the critical period for finasteride effects on development of male external genitalia in the rabbit. The fetal effects of maternal finasteride exposure during the period of embryonic and fetal development were evaluated in the rhesus monkey (gestation days 20 to 100), in a species and development period more predictive of specific effects in humans than the studies in rats and rabbits. Intravenous administration of finasteride to pregnant monkeys at doses as high as 800 ng/day (estimated maximal blood concentration of 1.86 ng/mL or about 930 times the highest estimated exposure of pregnant women to finasteride from semen of men taking 1 mg/day) resulted in no abnormalities in male fetuses.
In confirmation of the relevance of the rhesus model for human fetal development, oral administration of a dose of finasteride (2 mg/kg/day or approximately 120,000 times the highest estimated blood levels of finasteride from semen of men taking 1 mg/day) to pregnant monkeys resulted in external genital abnormalities in male fetuses. No other abnormalities were observed in male fetuses and no finasteride- related abnormalities were observed in female fetuses at any dose.
Breastfeeding
Nursing Mothers Finasteride
tablets is not indicated for use in women. It is not known whether finasteride is excreted in human milk.
Side effects
The most common adverse reactions, reported in ≥1% of patients treated with finasteride tablets and greater than in patients treated with placebo are: decreased libido, erectile dysfunction and ejaculation disorder. To report SUSPECTED ADVERSE REACTIONS, contact Ascend Laboratories, LLC at 1-877-272-7901 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
Clinical Trials Experience Because
clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Clinical Studies for finasteride tablets 1 mg in the Treatment of Male Pattern Hair Loss In three controlled clinical trials for finasteride tablets of 12-month duration, 1.4% of patients taking finasteride tablets (n=945) were discontinued due to adverse experiences that were considered to be possibly, probably or definitely drug-related (1.6% for placebo; n=934). Clinical adverse experiences that were reported as possibly, probably or definitely drug-related in > 1% of patients treated with finasteride tablets or placebo are presented in Table 1.
TABLE 1: Drug-Related Adverse Experiences for Finasteride tablets 1 mg (finasteride 1 mg) in Year 1 (%) MALE PATTERN HAIR LOSS Finasteride N=945 Placebo N=934 Decreased Libido 1.8
Erectile Dysfunction
1.3
Ejaculation Disorder
(Decreased Volume of Ejaculate) 1.2
Discontinuation
due to drug-related sexual adverse experiences 1.2
Integrated
analysis of clinical adverse experiences showed that during treatment with finasteride tablets, 36 (3.8%) of 945 men had reported one or more of these adverse experiences as compared to 20 (2.1%) of 934 men treated with placebo (p=0.04). Resolution occurred in men who discontinued therapy with finasteride tablets due to these side effects and in most of those who continued therapy. The incidence of each of the above adverse experiences decreased to < 0.3% by the fifth year of treatment with finasteride tablets.
In a study of finasteride 1 mg daily in healthy men, a median decrease in ejaculate volume of 0.3 mL (-11%) compared with 0.2 mL (-8%) for placebo was observed after 48 weeks of treatment. Two other studies showed that finasteride at 5 times the dosage of finasteride tablets (5 mg daily) produced significant median decreases of approximately 0.5 mL (-25%) compared to placebo in ejaculate volume, but this was reversible after discontinuation of treatment. In the�clinical studies with finasteride tablets, the incidences for breast tenderness and enlargement, hypersensitivity reactions, and testicular pain in finasteride-treated patients were not different from those in patients treated with placebo . Controlled Clinical Trials and Long-Term Open Extension Studies for finasteride tablets (finasteride 5 mg) and AVODART (dutasteride) in the Treatment of Benign Prostatic Hyperplasia In the finasteride tablets 5 mg Long-Term Efficacy and Safety Study (PLESS), a 4-year controlled clinical study, 3,040 patients between the ages of 45 and 78 with symptomatic BPH and an enlarged prostate were evaluated for safety over a period of 4 years (1,524 on finasteride tablets 5 mg/day and 1,516 on placebo). 3.7% (57 patients) treated with finasteride tablets 5 mg and 2.1% (32 patients) treated with placebo discontinued therapy as a result of adverse reactions related to sexual function, which are the most frequently reported adverse reactions.
Table 2 presents the only clinical adverse reactions considered possibly, probably or definitely drug related by the investigator, for which the incidence on finasteride tablets 5 mg was > 1% and greater than placebo over the 4 years of the study. In years 2 to 4 of the study, there was no significant difference between treatment groups in the incidences of impotence, decreased libido and ejaculation disorder. TABLE 2: Drug-Related Adverse Experiences for finasteride tablets 5 mg BENIGN PROSTATIC HYPERPLASIA Year 1 (%) Years 2, 3 and 4* (%) Finasteride 5 mg Placebo Finasteride 5 mg Placebo Impotence 8.1 3.7 5.1
Decreased Libido
6.4 3.4 2.6
Decreased Volume of Ejaculate
3.7 0.8 1.5
Ejaculation Disorder
0.8 0.1 0.2
Breast Enlargement
0.5 0.1 1.8
Breast Tenderness
0.4 0.1 0.7
Rash
0.5 0.2 0.5 0.1 *Combined Years 2 to 4 N = 1,524 and 1,516, finasteride vs placebo, respectively The adverse experience profiles in the 1-year, placebo-controlled, Phase III BPH studies and the 5-year open extensions with finasteride tablets 5 mg and PLESS were similar. There is no evidence of increased sexual adverse experiences with increased duration of treatment with finasteride tablets 5 mg. New reports of drug-related sexual adverse experiences decreased with duration of therapy.
During the 4- to 6-year placebo- and comparator-controlled Medical Therapy of Prostatic Symptoms (MTOPS) study that enrolled 3,047 men, there were 4 cases of breast cancer in men treated with finasteride tablets 5 mg but no cases in men not treated with finasteride tablets 5 mg. During the 4-year placebo-controlled PLESS study that enrolled 3,040 men, there were 2 cases of breast cancer in placebo-treated men, but no cases were reported in men treated with finasteride tablets 5 mg. During the 7-year placebo-controlled Prostate Cancer Prevention Trial (PCPT) that enrolled 18,882 men, there was 1 case of breast cancer in men treated with finasteride tablets, and 1 case of breast cancer in men treated with placebo.
The relationship between long-term use of finasteride and male breast neoplasia is currently unknown. The PCPT trial was a 7-year randomized, double-blind, placebo-controlled trial that enrolled 18,882 healthy men ≥55 years of age with a normal digital rectal examination and a PSA ≤3.0 ng/mL. Men received either finasteride tablets 5 mg (finasteride 5 mg) or placebo daily. Patients were evaluated annually with PSA and digital rectal exams.
Biopsies were performed for elevated PSA, an abnormal digital rectal exam, or the end of study. The incidence of Gleason score 8 to 10 prostate cancer was higher in men treated with finasteride (1.8%) than in those treated with placebo (1.1%). In a 4-year placebo-controlled clinical trial with another 5α-reductase inhibitor [AVODART (dutasteride)], similar results for Gleason score 8 to 10 prostate cancer were observed (1% dutasteride vs 0.5% placebo).
The clinical significance of these findings with respect to use of finasteride tablets by men is unknown. No clinical benefit has been demonstrated in patients with prostate cancer treated with finasteride tablets. Finasteride tablets is not approved to reduce the risk of developing prostate cancer.
Sexual Function Questionnaire A sexual function questionnaire was self-administered by patients participating in the two vertex baldness trials to detect more subtle changes in sexual function. At Month 12, statistically significant differences in favor of placebo were found in 3 of 4 domains (sexual interest, erections, and perception of sexual problems). However, no significant difference was seen in the question on overall satisfaction with sex life.
In one of the two vertex baldness studies, patients were questioned on non-scalp body hair growth. Finasteride tablets did not appear to affect non-scalp body hair.
Postmarketing Experience The
following adverse reactions have been identified during post approval use of finasteride tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Hypersensitivity Reaction: hypersensitivity reactions such as rash, pruritus, urticaria, and angioedema (including swelling of the lips, tongue, throat, and face); Reproductive System: sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, libido disorders, ejaculation disorders, and orgasm disorders; male infertility and/or poor seminal quality (normalization or improvement of seminal quality has been reported after discontinuation of finasteride); testicular pain; hematospermia. Neoplasms: male breast cancer; Breast disorders: breast tenderness and enlargement; Nervous System/Psychiatric: depression, suicidal ideation and behavior.
All information on this site is provided “as-is” for informational purposes only and is not a substitute for medical advice or treatment. You should consult with a medical professional if you have any questions about your health. Source: FDA Structured Product Labeling.