3.8% vs 2.1%men reporting a drug-related sexual side effect in year one, finasteride against placebo
Safety · Hair loss
Is finasteride safe? What the FDA-approved label reports
Neither the label nor the MedlinePlus page uses the word safe. They list what the trials measured, what was reported afterwards, and who should not take the drug, and each list has limits you should know before reading the numbers.
On 2 November 2026, the Propecia label showed 3.8% of men on finasteride reporting a drug-related sexual side effect in year one, against 2.1% on placebo. It also lists later reports, including depression and sexual dysfunction that continued after stopping, whose frequency it says it cannot always reliably estimate.
Source: the FDA-approved Propecia label on DailyMed, version 9, effective 14 October 2024, and the MedlinePlus finasteride page, both read in full 2 November 2026.
The short version
3.8%on finasteridereported a drug-related sexual side effect in year 1
2.1%on placeboreported the same in the same trials
Uncertainpost-marketing ratethe label says it is not always possible to estimate
Men onlywho it is fornot for women or children, and contraindicated in pregnancy
Finasteride safety: claims against the labelwhat gets said, and what the record shows, read 2 November 2026
They sayThe side effects are all in your head.
A risk flag
In the label's trials a measured difference showed up: 3.8% of men on finasteride against 2.1% on placebo reported a drug-related sexual effect in year one. That is small and it is real. See the receipt
They sayAny side effect goes away as soon as you stop.
Not that simple
The label says resolution occurred in men who stopped, and in most who kept going. It also lists post-marketing reports of sexual dysfunction that continued after stopping. See the receipt
They sayMillions take it, so it must be safe.
Depth, not safety
The number of users is not a safety measure. The label says its post-marketing reports come from a population of uncertain size, so it is not always possible to reliably estimate frequency or establish cause. See the receipt
What does this page read, and what does it leave out?
The Propecia label is the main document read in full here: the FDA-approved prescribing information for the finasteride tablet sold for male pattern hair loss, as published on DailyMed.[1] It is the regulator-reviewed summary of the company's trials and safety reports, and every rate on this page is quoted from it.
The MedlinePlus finasteride page was also read in full and is compared with the label below.[2] Neither is a research paper, and the published research was not read. For depth of record and how long results take, see the hair-loss trial-record guide.
What did the 12-month trials find?
The label pools three double-blind, placebo-controlled trials of 12 months, with 945 men on finasteride and 934 on placebo, aged 18 to 41 with mild to moderate hair loss.[1] It lists three drug-related effects reported by at least 1% of either group, charted below.
Percent of men reporting each effect in year 1 as drug-related, from Table 1 of the Propecia label: 945 men on finasteride and 934 on placebo, aged 18 to 41. "Any of the three" is the label's own integrated figure (36 men against 20).
Decreased libido: 1.8% on finasteride against 1.3% on placebo.
Erectile dysfunction: 1.3% against 0.7%.
Ejaculation disorder: 1.2% against 0.7%, with decreased semen volume 0.8% against 0.4%.[1]
Together, 36 of 945 men (3.8%) on finasteride reported one or more of these, against 20 of 934 (2.1%) on placebo, a difference the label gives as p=0.04.[1]
Stopping because of any drug-related adverse experience was 1.4% on finasteride and 1.6% on placebo, and stopping because of sexual effects was 1.2% against 0.9%.
A sexual function questionnaire in the two vertex-baldness trials found statistically significant differences in favor of placebo in three of four domains at month 12: sexual interest, erections and perception of sexual problems. There was no significant difference in overall satisfaction with sex life.
The label cautions that rates from one trial cannot be directly compared with another drug's and may not match everyday use.
What does the label say about stopping and about later reports?
Within the trials, the label says resolution occurred in men who stopped because of these effects and in most who kept taking the drug.[1] It adds that each effect's incidence fell to 0.3% or less by the fifth year of treatment.
Separately, the label lists reports gathered after approval:
Sexual dysfunction that continued after treatment was stopped, including erectile dysfunction, libido disorders, ejaculation disorders and orgasm disorders.
Male infertility or poor semen quality, with normalization or improvement reported after stopping.
Testicular pain and blood in semen.
Breast tenderness and enlargement, and male breast cancer.
Depression, suicidal ideation and behavior, which appear in this list and not in the trial table, and allergic reactions such as rash, itching, hives and swelling.
The label states that these reports are voluntary and come from a population of uncertain size, so it is not always possible to reliably estimate their frequency or establish a causal relationship.[1]
This page therefore gives no rate for them. A report is a signal to ask about, not proof that finasteride causes an effect or that it does not.
Do the label and MedlinePlus say the same thing?
MedlinePlus is a plain-language page from the same National Library of Medicine that hosts the label, last revised 15 June 2026.[2] It words several risks differently from the label.
Two US government texts on finasteride's riskssame four topics, read across, read 2 November 2026
Lists post-marketing reports of sexual dysfunction that continued after stopping, with frequency not always possible to estimate
Fertility
Lists male infertility or poor semen quality, with improvement reported after stopping
Cancer
High-grade prostate cancer seen at five times the dose in older men, significance for hair-loss use unknown; male breast cancer in post-marketing reports
Mood
Lists depression, suicidal ideation and behavior among post-marketing reports
Both texts agree on the main list: sexual effects, breast changes, depression and the pregnancy limit.
They differ in framing. The label ties persistence and cause to reports it cannot always count, while MedlinePlus states persistence, lower fertility and cancer risk as things that may happen.
PubMed papers whose title or abstract mention finasteride, hair loss and a harm word, counted 2 November 2026. A word match shows where the research is, not how often anything happens.
A word match includes papers that mention a harm only to rule it out, and it says nothing about how often anything happens.
It shows that the side effects have been studied beyond the label's table, and that this page has not read that research.
What does the label say about PSA and prostate cancer?
Finasteride lowers the blood marker PSA that is used to screen for prostate cancer. The label says any confirmed rise from the lowest value should be evaluated, even if it is still in the normal range for men not taking the drug.[1]
Mean serum PSA in the clinical studies of men aged 18 to 41, from section 5.2 of the label. A lower reading is expected on the drug, which is why a prescriber needs to know you take it.
The label also reports a finding from a different trial. In the 7-year Prostate Cancer Prevention Trial, men aged 55 and over taking five times the hair-loss dose had more high-grade prostate cancer than men on placebo: 1.8% against 1.1%.[1]
The label says the clinical significance of this for men using Propecia is unknown.
Gleason score 8 to 10 prostate cancer in men aged 55 and over taking five times the hair-loss dose, 18,882 men in all, from sections 5.3 and 6.1 of the label. A different drug strength, an older group and a different aim from hair-loss use.
Who should not take it?
The label says Propecia is for men only, is not indicated for women or children, and is contraindicated in women who are or may become pregnant, because it may cause abnormal development of external genitalia in a male fetus.[1] Women who are or may become pregnant should not handle crushed or broken tablets, which are coated to prevent contact while whole. It also advises caution with liver problems, since the drug is extensively processed by the liver.
In a 12-month study of 137 postmenopausal women, effectiveness could not be demonstrated.[1]
The label's clinical efficacy studies did not include men aged 65 and over.
Questions the label raises
1. Which of the label's reported effects matter most to you, and what would you do if one began?
2. Some reported effects continued after stopping. Ask the prescriber what that means in your case.
3. Depression is on the label. Tell the prescriber about any history before starting.
4. Planning a child, or living with someone who is or may be pregnant? Ask about that first.
5. A PSA blood test reads lower on this drug. Make sure whoever reads it knows.
Both sources point readers to the FDA's MedWatch program for reporting a suspected side effect.[5]
The label supplies the first box and names the second. The last two are where a prescriber earns the fee.
How should you use this page?
If you are asking whether it is safeThe sources list risks, not a verdictThey report a measured sexual side-effect difference in year one, later reports whose frequency is uncertain, and groups who must not take it. Weighing those against your own hair loss is a prescriber's decision.
If you are reading a forum or a sellerCheck it against the labelA claim of "no side effects" or of "always permanent" goes further than either source does. Their own wording is the floor to hold a claim against.
If you live with someone taking itPregnancy handling is on the labelThe label's rule is about pregnancy and about crushed or broken tablets. Ask a prescriber or pharmacist about your situation.
How this page was built
Method
The Propecia label was downloaded from DailyMed's structured product label service on 2 November 2026 and read in full, including the Patient Information, and the MedlinePlus page was read in full the same day. Every rate is quoted from the label: Table 1 for the trial rates, section 5.2 for PSA, sections 5.3 and 6.1 for the prostate cancer trial, section 6.2 for the post-marketing list, and sections 4, 5.1, 8 and 14.2 for who should not take it. The label's dose and strength figures are left out on purpose, because this is not a dosing page.
Limits: one label from one maker, no other manufacturer's label, and none of the published research read. The side-effect count is a word match and measures depth of record only (our grading rules are on the methodology page, and the evidence ladder shows how other topics compare). Nothing here is medical advice.
The exact query
Finasteride side effects: (finasteride[tiab] AND (alopecia[tiab] OR hair[tiab])) AND (adverse[tiab] OR "side effect*"[tiab] OR "sexual dysfunction"[tiab] OR erectile[tiab] OR libido[tiab] OR depress*[tiab] OR suicid*[tiab])
References
abcdefghij DailyMed (National Library of Medicine). Propecia (finasteride) tablet label, Organon LLC, version 9, effective 14 October 2024. Sections 1, 4, 5, 6, 8, 12 and 14 and the Patient Information were read in full. dailymed.nlm.nih.gov, read 2 November 2026.
ab MedlinePlus (National Library of Medicine). Finasteride: drug information, last revised 15 June 2026. medlineplus.gov, read 2 November 2026.
↑ PubMed search for finasteride and hair loss narrowed to papers that mention adverse or side effects, sexual dysfunction, erectile function, libido, depression or suicide in the title or abstract; the query is printed in the method section. pubmed.ncbi.nlm.nih.gov, read 2 November 2026.
↑ National Library of Medicine. MeSH publication type: Randomized Controlled Trial. ncbi.nlm.nih.gov.
↑ U.S. Food and Drug Administration. MedWatch: the FDA safety information and adverse event reporting program. The label and the MedlinePlus page both point to it. fda.gov, link checked 2 November 2026.
FAQ
Is finasteride safe?
Neither the FDA-approved Propecia label nor the MedlinePlus page says safe or unsafe. The label reports that 3.8% of men on finasteride and 2.1% on placebo had a drug-related sexual side effect in the first year of its trials, lists later reports whose frequency it says it cannot always reliably estimate, and names groups who should not take it. Whether it suits you is a decision for a prescriber.
What side effects does the Propecia label list?
In its trials: decreased libido, erectile dysfunction and ejaculation disorder, each reported by about 1 to 2% of men. After approval: sexual dysfunction that continued after stopping, male infertility or poor semen quality, testicular pain, blood in semen, breast tenderness and enlargement, male breast cancer, and depression with suicidal ideation.
Do finasteride side effects go away when you stop?
In the label's trials, resolution occurred in men who stopped and in most who continued. The label also lists post-marketing reports of sexual dysfunction that continued after stopping, and says it is not always possible to reliably estimate their frequency.
Does finasteride affect a PSA test?
Yes. The label says it lowers PSA, from a mean of 0.7 to 0.5 ng/mL at 12 months in men 18 to 41, and that any confirmed rise from the lowest value should be evaluated. Tell whoever reads the test that you take it.
Can women use or handle finasteride?
The label says it is for men only and is contraindicated in women who are or may become pregnant. Women who are or may become pregnant should not handle crushed or broken tablets.
Bottom line
The Propecia label reports a small, measured sexual side-effect difference in year one, later reports whose frequency is uncertain, a lower PSA reading, and firm limits on who should take it. Hold any claim of "totally safe" or "always permanent" up against that wording, then take the specifics to a prescriber.
How do I cite this page?
Cite the page and the date its figures were read. Every count here is a count of records matching a published query on the day it was read, so it can move; the method box on this page prints the query so you can re-run it.
APA
Whitepill editorial desk. (2026, November 2). Is finasteride safe? What the FDA-approved label reports. Whitepill. https://whitepill.dev/articles/is-finasteride-safe-what-the-fda-label-reports
BibTeX
@online{whitepill_is_finasteride_safe_what, author = {{Whitepill editorial desk}}, title = {Is finasteride safe? What the FDA-approved label reports}, year = {2026}, month = nov, url = {https://whitepill.dev/articles/is-finasteride-safe-what-the-fda-label-reports}, note = {Last modified 2026-11-02}
}
Published 2 November 2026. Last modified 2 November 2026. Where a figure rests on secondary reporting, the page says so; do not present that as a primary source.
What has changed on this page?
new Published. Every figure is quoted from the Propecia label on DailyMed (version 9, effective 14 October 2024), which was read in full on 2 November 2026.