Drugs › 5-alpha reductase inhibitor
Brand name · Finasteride
Proscar: adverse event reports filed with FDA
1,685 reports list it as a suspect or interacting product, 2004–2026. Class: 5-alpha reductase inhibitor.
- 1,685
- reports as suspect product
- 0% of all reports · about 75 a year
- 17
- reports, 12 months to June 2026
- 21 in the 12 months before
- 73.4%
- marked serious by the reporter
- 62.8% across the class
- 4.2%
- record death among outcomes, as reported
- 71 reports · not verified by FDA
Between January 2004 and May 2026, 1,685 adverse event reports received by FDA list the brand name Proscar (finasteride) as a suspect or interacting product. Reports that mention it only as a concomitant medication (6,427) are left out of every figure here.
In the 12 months to June 2026, 17 reports listed it, down 19% from 21 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 75 reports a year and 0% of the 20,646,523 reports in the database, and 6.8% of the reports for the 5-alpha reductase inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded erectile dysfunction (22.4%), sexual dysfunction (17.7%) and depression (15.7%). A report can list several reactions, so shares add to more than 100%; 765 different terms appear across these reports. Erectile dysfunction is recorded in 22.4% of these reports, a larger share than in the median 5-alpha reductase inhibitor drug (14.5%).
73.4% of the reports are marked serious by the reporter (62.8% across the class); 4.2% record death among the outcomes and 25.5% record hospitalisation, as reported. 42.1% of the reports came from consumers, and the largest patient age group is 75 and over (17.6%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Proscar reports recording the termmedian drug in 5-alpha reductase inhibitor
- Erectile dysfunctiondifficulty getting or keeping an erection22.4%378
- Sexual dysfunctiona sexual problem17.7%299
- Depressionlow mood15.7%265
- Anxietyanxiety14.2%239
- Libido decreasedreduced sex drive10.3%174
- Drug administration errora mistake in giving the medicine9.6%162
- Cognitive disorderproblems with thinking or memory9.2%155
- Fatiguetiredness8%135
- Gynaecomastiabreast enlargement in men7.7%130
- Loss of libido7.2%122
- Drug ineffectivethe medicine did not work as expected6.8%115
- Insomniadifficulty sleeping5.8%97
- Astheniaweakness or lack of energy5.5%92
- Wrong technique in product usage processthe product was used in the wrong way5.3%90
- Ejaculation disorder5%85
- Prostate cancer4.8%81
- Wrong technique in drug usage processthe medicine was used in the wrong way4.7%80
- Dizzinesslight-headedness or unsteadiness4.4%74
- Back painback pain4.3%73
- Hypertensionhigh blood pressure4.3%72
- Urinary retentionbeing unable to empty the bladder3.9%65
- Semen volume decreased3.8%64
- Testicular pain3.8%64
- Arthralgiajoint pain3.7%62
- Ejaculation failure3.4%58
- Painpain, site not specified3.3%55
- Dyspnoeashortness of breath3.1%53
- Suicidal ideationthoughts of suicide3.1%52
Top 30 of 765 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 5 drugs in the 5-alpha reductase inhibitor class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 24,827 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 59.1% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Benign prostatic hyperplasia | 438 | 26% |
| Alopecia | 195 | 11.6% |
| Androgenetic alopecia | 113 | 6.7% |
| Prostatomegaly | 87 | 5.2% |
| Prostate cancer | 41 | 2.4% |
| Prostatic disorder | 11 | 0.7% |
The indication field is filled in by the reporter and is often blank; shares are of all 1,685 reports.
In context
| Measure | Proscar | 5-alpha reductase inhibitor | All reports |
|---|---|---|---|
| Reports as suspect product | 1,685 | 24,827 | 20,646,523 |
| Share of that pool | — | 6.8% | 0% |
| Reports, latest 12 months | 17 | — | 1,332,454 |
| Marked serious | 73.4% | 62.8% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 42 | 48 | 91 |
| Hospitalisation recorded, per 1,000 reports | 255 | 153 | 213 |
| Consumer-filed share | 42.1% | 60.8% | 45.8% |
| Top term, share of reports | Erectile dysfunction 22.4% | median 14.5% | 0.1% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the 5-alpha reductase inhibitor class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Finasteride | generic | 15,517 | 2,671 | 59.9% |
| Propecia | brand | 4,320 | 18 | 67.4% |
| Dutasteride | generic | 2,726 | 151 | 74.7% |
| Jalyn | brand | 579 | 0 | 20.4% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Proscar reports
How many adverse event reports has FDA received for Proscar?
1,685 reports list Proscar as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 17 of them arrived in the latest 12 months. Another 6,427 list it only as a concomitant medication.
What reactions are recorded in Proscar reports?
erectile dysfunction (22.4%), sexual dysfunction (17.7%), depression (15.7%), anxiety (14.2%) and libido decreased (10.3%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Proscar was responsible.
How serious are the reports?
73.4% are marked serious by the reporter. Among the outcomes recorded, 4.2% of reports include death and 25.5% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
consumer or non-health professional (42.1%), physician (30.2%) and other health professional (17.1%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Proscar rising?
17 reports in the 12 months to June 2026, down 19% from 21 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Proscar was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Proscar?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Proscar as a suspect or interacting product; reports listing it only as a concomitant medication (6,427) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.