Finasteride
Also sold as Finasteride
From 11 official FDA drug labels · RxNorm 200172
What it is used for
These are the uses the FDA has approved for this label. Using it for anything else is “off-label”: ask your prescriber why.
1 INDICATIONS AND USAGE Finasteride tablets are indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY . Efficacy in bitemporal recession has not been established. Finasteride tablets are not indicated for use in women. Finasteride is a 5α-reductase inhibitor indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY (1) . Finasteride tablets are not indicated for use in women ( 1 , 4 , 5.1 ).
How to take it
2 DOSAGE AND ADMINISTRATION Finasteride tablets may be administered with or without meals. The recommended dose of finasteride 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 (2) . One tablet (1 mg) taken once daily (2) . In general, daily use for three months or more is necessary before benefit is observed (2) .
Do not take it if
4 CONTRAINDICATIONS Finasteride tablets are 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. [See Warnings and Precautions (5.1) , Use in Specific Populations (8.1) , How Supplied/Storage and Handling (16) and Patient Counseling Information (17). ] 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 (4) .
Serious warnings and precautions
5 WARNINGS AND PRECAUTIONS Finasteride 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 causes a decrease in serum PSA levels. Any confirmed increase in PSA while on finasteride 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 (5.2) . 5α-reductase inhibitors may increase the risk of high-grade prostate cancer (5.3, 6.1) . 5.1 Exposure of Women - Risk to Male Fetus Finasteride 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. [See Indications and Usage (1) , Contraindications (4) , Use in Specific Populations (8.1) , How Supplied/Storage and Handling (16) and Patient Counseling Information (17). ] 5.2 Effects on Prostate Specific Antigen (PSA) In clinical studies with 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, 5 mg when used in older men who have benign prostatic hyperplasia (BPH), PSA levels are decreased by approximately 50%. Other studies with finasteride 5 mg 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 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 may also affect PSA test results. 5.3 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 ng/mL at baseline taking finasteride 5 mg/day (5 times the dose of finasteride) 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%). [See Adverse Reactions (6.1) .] 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. 5.4 Pediatric Patients Finasteride is not indicated for use in pediatric patients [see Use in Specific Populations (8.4) ] .
Common side effects
From the label’s clinical-trial and reporting data. Serious problems are under the warnings above.
6 ADVERSE REACTIONS The most common adverse reactions, reported in ≥1% of patients treated with finasteride and greater than in patients treated with placebo are: decreased libido, erectile dysfunction and ejaculation disorder (6.1) . To report SUSPECTED ADVERSE REACTIONS, contact Rising Health, LLC at 1-833-395-6928 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 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 1 mg in the Treatment of Male Pattern Hair Loss In three controlled clinical trials for finasteride of 12-month duration, 1.4% of patients taking finasteride (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 or placebo are presented in Table 1. TABLE 1: Drug-Related Adverse Experiences for Finasteride 1 mg in Year 1 (%) MALE PATTERN HAIR LOSS Finasteride N=945 Placebo N=934 Decreased Libido 1.8 1.3 Erectile Dysfunction 1.3 0.7 Ejaculation Disorder (Decreased Volume of Ejaculate) 1.2 (0.8) 0.7 (0.4) Discontinuation due to drug-related sexual adverse experiences 1.2 0.9 Integrated analysis of clinical adverse experiences showed that during treatment with finasteride, 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 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. 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 (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, 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 5 mg and AVODART (dutasteride) in the Treatment of Benign Prostatic Hyperplasia In the finasteride 5 mg long-term efficacy and safety study, a 4-year controlled clinical study, 3040 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 (1524 on finasteride 5 mg/day and 1516 on placebo). 3.7% (57 patients) treated with finasteride 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 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 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 5.1 Decreased Libido 6.4 3.4 2.6 2.6 Decreased Volume of Ejaculate 3.7 0.8 1.5 0.5 Ejaculation Disorder 0.8 0.1 0.2 0.1 Breast Enlargement 0.5 0.1 1.8 1.1 Breast Tenderness 0.4 0.1 0.7 0.3 Rash 0.5 0.2 0.5 0.1 *Combined Years 2 to 4 N = 1524 and 1516, 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 5 mg and long-term efficacy and safety study were similar. There is no evidence of increased sexual adverse experiences with increased duration of treatment with finasteride 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 3047 men, there were 4 cases of breast cancer in men treated with finasteride 5 mg but no cases in men not treated with finasteride 5 mg. During the 4-year placebo-controlled long-term efficacy and safety study that enrolled 3040 men, there were 2 cases of breast cancer in placebo-treated men, but no cases were reported in men treated with finasteride 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 5 mg, 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 ng/mL. Men received either 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 by men is unknown. No clinical benefit has been demonstrated in patients with prostate cancer treated with finasteride 5 mg. Finasteride 5 mg 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 did not appear to affect non-scalp body hair. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of finasteride. 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.
Taking it with other medicines
7 DRUG INTERACTIONS 7.1 Cytochrome P450-Linked Drug Metabolizing Enzyme System No drug interactions of clinical importance have been identified. Finasteride does not appear to affect the cytochrome P450-linked drug-metabolizing enzyme system. Compounds that have been tested in man include antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found. 7.2 Other Concomitant Therapy Although specific interaction studies were not performed, finasteride doses of 1 mg or more were concomitantly used in clinical studies with acetaminophen, acetylsalicylic acid, α-blockers, analgesics, angiotensin-converting enzyme (ACE) inhibitors, anticonvulsants, benzodiazepines, beta blockers, calcium-channel blockers, cardiac nitrates, diuretics, H 2 antagonists, HMG-CoA reductase inhibitors, prostaglandin synthetase inhibitors (also referred to as NSAIDs), and quinolone anti-infectives without evidence of clinically significant adverse interactions.
If you are pregnant or breastfeeding
8.1 Pregnancy Pregnancy Category X [see Contraindications (4) ] . Finasteride is contraindicated for use in women who are or may become pregnant. Finasteride 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. 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 1 mg/day that measured finasteride concentrations in semen [see Clinical Pharmacology (12.3) ] . 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.
If you take too much
10 OVERDOSAGE In clinical studies, single doses of finasteride up to 400 mg and multiple doses of finasteride up to 80 mg/day for three months did not result in adverse reactions. Until further experience is obtained, no specific treatment for an overdose with finasteride can be recommended. Significant lethality was observed in male and female mice at single oral doses of 1500 mg/m 2 (500 mg/kg) and in female and male rats at single oral doses of 2360 mg/m 2 (400 mg/kg) and 5900 mg/m 2 (1000 mg/kg), respectively.
Forms and strengths available
From RxNorm. Which forms and strengths are actually stocked varies by pharmacy and country.
Reactions people have reported
These are counts from 8 voluntary reports to the FDA. They show what has been reported — they are not how common a side effect is, and they do not prove the medicine caused it.
Recalls
Research & studies
Recent higher-quality studies about Finasteride, from PubMed. We link to the source — titles only. This is not medical advice.
Questions to ask your doctor or pharmacist
- Is this the right medicine for my condition, and how long should I take it?
- What side effects should I watch for, and which ones need urgent attention?
- Does this interact with my other medicines, supplements, or alcohol?
- What should I do if I miss a dose or take too much?
Why you can trust this
Everything above comes from official FDA drug labels (openFDA), not written by us. Here are the exact labels used.
- FDA labelRising Pharma Holdings, Inc.· version 8· published Apr 19, 2024· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelREMEDYREPACK INC.· version 1· published Jun 30, 2026· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelDirect_Rx· version 2· published Dec 16, 2025· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelProficient Rx LP· version 1· published Apr 1, 2023· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelExelan Pharmaceuticals Inc.· version 6· published Oct 30, 2020· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelCardinal Health 107, LLC· version 3· published Apr 27, 2026· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelNuCare Pharmaceuticals, Inc.· version 2· published Dec 24, 2024· retrieved Oct 19, 2026· View this label on DailyMed
- FDA labelAtlantic Biologicals Corps· version 6· published Jun 24, 2025· retrieved Oct 19, 2026· View this label on DailyMed