Finasteride, dutasteride and ED: what the labels say

Status: FDA-approved for another condition, not for ED (finasteride for an enlarged prostate and for male pattern hair loss; dutasteride for an enlarged prostate). Source: PROSCAR, PROPECIA and AVODART prescribing information, DailyMed, checked 2026-10-17.

The short version: finasteride and dutasteride belong to a group of medicines called 5-alpha reductase inhibitors, which lower the hormone DHT. Both labels list erectile dysfunction among their most common side effects. In the placebo-controlled trials the extra risk was small, it showed up mostly early in treatment, and most men did not report it at all. The labels also carry reports of sexual problems that continued after the medicine was stopped. The PROSCAR label calls these reports rare and says plainly that the drug’s independent role in them is unknown. This page sets out what each label and the research actually show, and what to raise with your prescriber before changing anything.

Can finasteride cause ED?

Yes, it can in some men. The label for PROPECIA, the finasteride tablet for male pattern hair loss, names decreased libido, erectile dysfunction and ejaculation disorder as its most common adverse reactions, reported more often than on placebo (PROPECIA prescribing information, DailyMed). The label for PROSCAR, the finasteride tablet for an enlarged prostate, says “impotence and decreased libido may occur in patients treated with PROSCAR” (PROSCAR prescribing information, DailyMed). MedlinePlus also includes finasteride and dutasteride on its list of drugs that may cause erection problems (MedlinePlus).

What the labels do not say is that it happens to most men. The numbers below show how often it was reported in the trials, and how close those rates were to placebo.

How common was ED in the finasteride trials?

In the trials behind both finasteride labels, ED was reported by a small minority of men, and by some men on placebo too. The gap between the drug and placebo was a few percentage points at most.

Sources: PROPECIA label, section 6.1; PROSCAR label, section 6.1. Both labels count only events the investigators judged possibly, probably or definitely drug related.

Two details from the labels help put these numbers in context:

• The difference faded over time in the prostate trial. The PROSCAR label says that “in years 2-4 of the study, there was no significant difference between treatment groups in the incidences of impotence, decreased libido and ejaculation disorder.”
• Most hair loss trial effects resolved. The PROPECIA label says resolution “occurred in men who discontinued therapy with PROPECIA due to these side effects and in most of those who continued therapy.” Overall, 3.8% of men on finasteride and 2.1% on placebo reported one or more sexual side effects in those trials, and 1.2% versus 0.9% stopped because of them.

Pooled analyses of randomized trials point the same way, with one split. A 2016 meta-analysis of 17 trials found a higher risk of ED with these medicines in men treated for an enlarged prostate (relative risk 1.55) but no statistically significant increase in men treated for hair loss (Liu et al., Journal of Sexual Medicine, 2016). A 2017 meta-analysis of 17 placebo-controlled prostate trials also found a raised risk of ED (odds ratio 1.47) and of low desire, and reported that the risk decreased as trial follow-up went on (Corona et al., Andrology, 2017).

What does the label say about persistent sexual effects?

Both finasteride labels list reports of sexual problems that continued after treatment stopped. The PROPECIA label lists “sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, libido disorders, ejaculation disorders, and orgasm disorders,” along with male infertility or poor semen quality, depression, and suicidal ideation and behavior (PROPECIA label, DailyMed). Its patient information repeats this in plain words, including “difficulty in achieving an erection that continued after stopping the medication.”

These come from postmarketing reports, not from the controlled trials, and the labels are careful about what that means. The PROSCAR label explains that such events “are reported voluntarily from a population of uncertain size,” so “it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.” About the persistent sexual reports specifically, it adds that “most men were older and were taking concomitant medications and/or had co-morbid conditions” and that “the independent role of PROSCAR in these events is unknown” (PROSCAR label, DailyMed).

The American Urological Association guideline on enlarged prostate describes the persistent picture, often called post-finasteride syndrome, as “controversial and poorly-defined,” and notes that concerns about it prompted the FDA to add a warning to these labels, while adding that the robustness of the data behind that change, which come from patient reports rather than prospective trials, “remains unclear” (AUA guideline, Management of Lower Urinary Tract Symptoms Attributed to BPH, amended 2023). Some research describes men in whom it lasted. In one follow-up study of 54 otherwise healthy young men who already had sexual side effects lasting at least 3 months after stopping finasteride for hair loss, 96% still reported them when reassessed 9 to 16 months later (Irwig, Journal of Sexual Medicine, 2012). That study selected men who already had persistent symptoms, so it describes their course but cannot say how often this happens among everyone who takes the medicine.

What about dutasteride?

Dutasteride, sold as AVODART for an enlarged prostate, shows a similar pattern. Impotence, decreased libido, ejaculation disorders and breast disorders are its most common adverse reactions. In its pivotal trials, impotence was reported by 4.7% of men on dutasteride and 1.7% on placebo in the first 6 months, and the rates were close to placebo after that (AVODART prescribing information, DailyMed).

Source: AVODART label, section 6.1. The label adds that in three 4-year trials there was “no evidence of increased sexual adverse reactions” with longer treatment.

Dutasteride labeling on DailyMed also carries persistence wording. A current generic dutasteride label says these sexual adverse reactions “may persist after treatment discontinuation. The role of dutasteride in this persistence is unknown,” and its patient information notes that depressed mood has been reported (dutasteride capsules prescribing information, DailyMed). One practical difference: dutasteride stays in the body for a long time. The AVODART label says blood levels remain detectable for up to 4 to 6 months after treatment ends.

The 2017 prostate meta-analysis found no difference between finasteride and dutasteride in the risk of ED or low desire (Corona et al., 2017).

Is topical or compounded finasteride safer for erections?

Status: Compounded: not FDA-approved (applies to compounded topical finasteride products). Source: FDA compounding risk alert on topical finasteride, checked 2026-10-17.

Not necessarily. In April 2025 the FDA said there is no FDA-approved topical form of finasteride, and that compounded topical finasteride products “do not have FDA-approved labeling” (FDA, compounded topical finasteride alert). The agency received 32 adverse event reports between 2019 and 2024 describing effects consistent with oral finasteride, including erectile dysfunction, decreased libido, depression and suicidal ideation, and said that “absorption of finasteride through the skin into the bloodstream is expected.”

The FDA also noted that most of those reports said the effects continued after the product was stopped, and that some men had been told by prescribers that a topical product carried no risk. A topical form also brings its own concern: a greater chance of transfer to others, which matters because finasteride must be kept away from pregnant women. Reports like these cannot show how often problems happen, but they do show that “topical” does not mean free of the side effects on the oral labels.

Why is it hard to tell whether finasteride is the cause?

Because ED is common in exactly the men who take these medicines, and several other things can be going on at once. The PROSCAR trial showed ED in 5.1% of men on placebo in later years, a reminder that it happens without the drug too. A large UK records study of men with an enlarged prostate, all free of known risk factors for ED when they entered it, found that the risk of ED rose with how long they had had the prostate condition, whatever treatment they were on. In that study, men on a 5-alpha reductase inhibitor alone did not have a higher risk of ED than men on an alpha blocker alone, and men taking finasteride for hair loss did not have a higher risk than untreated men with hair loss (Hagberg et al., BMJ, 2016).

That observational finding sits alongside the trial data showing a small raised risk, especially early in treatment, so the honest summary is that these medicines can contribute to ED for some men without being the explanation every time. Expectation may play a part too: in one small study of a blood pressure medicine, men who were told about its possible effect on erections reported ED more often (Silvestri et al., European Heart Journal, 2003), which our guide to medicines that can affect erections describes. Changes in desire and hormones also overlap, which our guides on hormones and ED and ED and low testosterone cover.

What should you ask before stopping?

Ask your prescriber first, and do not stop on your own. The NIH advises, “Do not stop taking any medicines on your own. Talk with your health care professional first,” and notes they may suggest a different dose or a different medicine (NIDDK, Treatment for ED). For an enlarged prostate the medicine is treating a real condition, and the AUA guideline expects clinicians to discuss the risk of sexual side effects with patients before starting a 5-alpha reductase inhibitor (AUA guideline).

Useful questions to bring:

• Timing. “My erections changed around when I started this. Could the two be linked, or is something else more likely?”
• The reason I take it. “What happens to my prostate symptoms, or my hair, if I stop or switch?”
• Alternatives. “Are there other treatments for my condition with a different side-effect profile?”
• Other causes. “Should we check blood pressure, blood sugar or hormones as well?”
• PSA tests. “Does this medicine affect my PSA result?” Both finasteride and dutasteride lower PSA readings, and the labels tell prescribers how to interpret the test while you take them.
• Mood. “What should I watch for?” The finasteride labels list depression and suicidal thoughts among reported effects, and dutasteride labeling notes depressed mood.

Our guide to talking to a doctor about ED covers how to raise the subject if it feels awkward.

If you are unsure whether it is time to book that visit, our guide on when to see a doctor about ED sets out the signs that mean sooner rather than later.

Sources

Every clinical statement on this page traces to one of these sources:

• PROPECIA (finasteride) prescribing information and patient information, DailyMed, revised 11/2023. Hair loss trial rates (ED 1.3% vs 0.7%), resolution statement, postmarketing reports of sexual dysfunction continuing after discontinuation, depression and suicidal ideation: dailymed.nlm.nih.gov, PROPECIA label
• PROSCAR (finasteride) prescribing information, DailyMed, revised 03/2026. PLESS drug-related impotence 8.1% vs 3.7% in year 1 and 5.1% vs 5.1% in years 2 to 4, postmarketing reports with an unknown independent role, PSA guidance: dailymed.nlm.nih.gov, PROSCAR label
• AVODART (dutasteride) prescribing information, DailyMed (Physicians Total Care listing, October 2011). Impotence by time of onset vs placebo, no increase with longer treatment, detectable for 4 to 6 months after stopping: dailymed.nlm.nih.gov, AVODART label
• Dutasteride capsules prescribing information (Aurobindo), DailyMed, revised 01/2023. Sexual adverse reactions may persist after discontinuation, role unknown; depressed mood reported: dailymed.nlm.nih.gov, dutasteride label
• U.S. Food and Drug Administration, FDA alerts health care providers, compounders and consumers of potential risks associated with compounded topical finasteride products, April 22, 2025: fda.gov, compounded topical finasteride alert
• American Urological Association, Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia (2021, amended 2023). Counseling on sexual side effects before starting a 5-alpha reductase inhibitor; post-finasteride syndrome described as controversial and poorly defined, with the data behind the label warning described as unclear: auanet.org, AUA BPH guideline PDF
• Corona G, et al. Sexual dysfunction in subjects treated with inhibitors of 5α-reductase for benign prostatic hyperplasia: a comprehensive review and meta-analysis. Andrology, 2017: pubmed.ncbi.nlm.nih.gov/28453908
• Liu L, et al. Effect of 5α-reductase inhibitors on sexual function: a meta-analysis and systematic review of randomized controlled trials. Journal of Sexual Medicine, 2016: pubmed.ncbi.nlm.nih.gov/27475241
• Hagberg KW, et al. Risk of erectile dysfunction associated with use of 5-α reductase inhibitors for benign prostatic hyperplasia or alopecia: population based studies using the Clinical Practice Research Datalink. BMJ, 2016: pubmed.ncbi.nlm.nih.gov/27659058
• Silvestri A, et al. Report of erectile dysfunction after therapy with beta-blockers is related to patient knowledge of side effects and is reversed by placebo. European Heart Journal, 2003: pubmed.ncbi.nlm.nih.gov/14585251
• Irwig MS. Persistent sexual side effects of finasteride: could they be permanent? Journal of Sexual Medicine, 2012: pubmed.ncbi.nlm.nih.gov/22789024
• NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases, NIH), Treatment for Erectile Dysfunction. “Do not stop taking any medicines on your own”: niddk.nih.gov, ED treatment
• MedlinePlus Medical Encyclopedia, Drugs that may cause erection problems. Finasteride and dutasteride on the list: medlineplus.gov/ency/article/004024.htm