Enlarged prostate (BPH) and ED, including tadalafil's BPH approval
The short answer
An enlarged prostate (BPH) and ED often show up in the same men. The NIH lists enlarged prostate among the conditions that can lead to ED, and a large survey ties worse urinary symptoms to more sexual problems. Some BPH medicines can affect erections or ejaculation, and tadalafil is FDA-approved for BPH symptoms, ED, or both together.
In short: an enlarged prostate, which doctors call benign prostatic hyperplasia (BPH), and erectile dysfunction (ED) are both common in men over 50, and they often turn up together. The National Institutes of Health (NIH) lists enlarged prostate among the conditions that can lead to ED, and lists ED among the conditions that make BPH more likely. The link runs in other ways too: some BPH medicines can affect erections, desire or ejaculation, BPH surgery can affect sexual function, and one ED medicine, tadalafil, is also FDA-approved for BPH symptoms. This guide walks through each of those, using the drug labels and guideline sources, and ends with what to raise with a clinician.
Is an enlarged prostate linked to ED?
Yes, the two are closely linked, though the research shows an association rather than proof that one causes the other in any given man. The NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists “enlarged prostate” among the problems of the male reproductive system that can lead to ED (NIDDK, Symptoms & Causes of ED), and its BPH page lists ED among the conditions that make BPH more likely, along with heart and blood vessel disease, type 2 diabetes, obesity and chronic kidney disease (NIDDK, Enlarged Prostate (BPH)). The American Urological Association (AUA) ED guideline says urinary symptoms from BPH are reported in up to 72% of men with ED, that the two are “independent risk factors for each other,” and that they share risk factors such as age, obesity, high blood pressure and diabetes (AUA Erectile Dysfunction Guideline). Our guide to what causes erectile dysfunction puts the prostate alongside the other physical, medical and mental causes.
What does the research on urinary symptoms and erections show?
The best-known evidence is a large survey, not a trial. The Multinational Survey of the Aging Male (MSAM-7) analyzed questionnaires from 12,815 men aged 50 to 80 in the US and six European countries, using validated scores for both urinary symptoms and erectile function. Sexual problems, and how much they bothered men, were “strongly related to both age and severity” of lower urinary tract symptoms (LUTS), and the link held after accounting for diabetes, high blood pressure, heart disease and high cholesterol (Rosen et al., Eur Urol 2003). The authors concluded that LUTS are independent risk factors for sexual dysfunction in older men and that sexual issues should be considered when BPH is managed. A survey like this can show that the two travel together. It cannot show that the prostate is the reason for one man’s ED, which is why a full check matters more than any one number.
| What the sources say | Type of evidence | Source |
|---|---|---|
| Enlarged prostate is among the conditions that can lead to ED | NIH patient guidance | NIDDK |
| ED is among the conditions that make BPH more likely | NIH patient guidance | NIDDK |
| Urinary symptoms from BPH reported in up to 72% of men with ED | Guideline summary of studies | AUA ED |
| Worse urinary symptoms go with more sexual problems, beyond other illness | Survey of 12,815 men aged 50 to 80 | MSAM-7 |
What is BPH, and how common is it?
BPH is a condition in which the prostate grows larger than normal, and the growth is not caused by cancer. NIDDK estimates it affects 5% to 6% of men aged 40 to 64 and 29% to 33% of men 65 and older, and calls it the most common prostate problem in men over 50 (NIDDK, Enlarged Prostate (BPH)). The prostate sits below the bladder and wraps around the urethra, so as it grows it can squeeze the tube urine passes through. Common symptoms include trouble starting a stream or emptying the bladder, a weak or interrupted stream, dribbling at the end, getting up at night to urinate, urgency and frequency. NIDDK notes that symptoms do not track neatly with prostate size: a large prostate can cause few problems, and a slightly enlarged one can cause more.
Some urinary symptoms come from other problems, including bladder problems, urinary tract infections, prostatitis and prostate cancer, so NIDDK advises discussing any urinary symptoms with a health care professional. The AUA BPH guideline says that bothersome symptoms are the main reason men seek treatment and that decisions should be shared between patient and clinician (AUA BPH Guideline, 2026).
Can BPH medicines affect erections or ejaculation?
Some can. NIDDK describes three groups of BPH medicines: alpha-blockers, which relax the muscles of the bladder neck and prostate; 5-alpha reductase inhibitors (5-ARIs) such as finasteride and dutasteride, which help stop the prostate growing or shrink it; and PDE5 inhibitors, which relax the muscles around the bladder, bladder neck and prostate (NIDDK, Enlarged Prostate (BPH)). The labels for the first two groups list sexual side effects; for finasteride and dutasteride these were reported mostly in the first months of treatment. The table sums up what each label reports.
| Medicine (label) | Sexual effects the label reports |
|---|---|
| Finasteride (PROSCAR) | Impotence, lower libido, less ejaculate and ejaculation disorders; more often than placebo in year 1, no significant difference in years 2 to 4 |
| Dutasteride (AVODART) | Impotence, lower libido and ejaculation disorders, most often in the first 6 months; may persist after stopping, with dutasteride’s role unknown |
| Tamsulosin, an alpha-blocker (JALYN) | Abnormal ejaculation, including retrograde and decreased ejaculation; rare priapism |
| Dutasteride plus tamsulosin (JALYN) | Ejaculation disorders in 11% on the combination, against 2% on dutasteride and 4% on tamsulosin alone |
Sources: PROSCAR prescribing information, DailyMed; AVODART prescribing information, DailyMed; JALYN prescribing information, DailyMed.
NIDDK’s advice applies here: a health care professional may review whether a medicine you need is playing a part in ED and may suggest a different dose or medicine, but “Do not stop taking any medicines on your own” (NIDDK, Treatment for ED).
Do finasteride and dutasteride cause ED?
They can contribute in some men, and the labels give numbers. In the four-year PLESS trial in men with an enlarged prostate, drug-related impotence was reported by 8.1% on finasteride against 3.7% on placebo in the first year, and lower libido by 6.4% against 3.4%. In years 2 to 4 the rates were the same in both groups (5.1% for impotence and 2.6% for lower libido), and the label says new sexual side effects became less frequent the longer men stayed on it. The label also notes rare postmarketing reports of sexual problems that continued after stopping, adding that most of those men were older, on other medicines or had other conditions, and that finasteride’s independent role “is unknown” (PROSCAR label, sections 6.1 and 6.2).
The dutasteride label shows the same early pattern. In its placebo-controlled BPH trials, impotence that began in months 0 to 6 was reported by 4.7% on dutasteride against 1.7% on placebo, while impotence that began in months 19 to 24 was reported by 0.8% against 0.9%. The label says these sexual effects may persist after treatment stops and that “the role of dutasteride in this persistence is unknown” (AVODART label, section 6.1). Our page on finasteride, dutasteride and ED goes through both labels in more detail, and the wider list is in our guide to medications that can affect erections.
Does combining BPH medicines change the picture?
The labels show higher rates of some sexual side effects when two BPH medicines are used together. In the MTOPS study, 3,047 men with BPH were followed for 4 to 6 years on placebo, the alpha-blocker doxazosin, finasteride, or both. Drug-related impotence was reported by 12.2% on placebo, 14.4% on doxazosin, 18.5% on finasteride and 22.6% on the combination, and abnormal ejaculation by 2.3%, 4.5%, 7.2% and 14.1%. For abnormal ejaculation, the label says the rate on the combination was comparable to the two single-medicine rates added together. The label cautions that the study was not designed to compare side effects statistically between groups (PROSCAR label, section 6.1). NIDDK notes that an alpha-blocker plus a 5-ARI may work better for urinary symptoms than one medicine alone (NIDDK, Enlarged Prostate (BPH)), so the choice is a trade-off a urologist can weigh with you.
What is tadalafil approved for in BPH?
Tadalafil, sold by Eli Lilly as Cialis, has three approved uses on its label: ED, “the signs and symptoms of benign prostatic hyperplasia (BPH)”, and ED together with BPH symptoms in the same man (Cialis label, sections 1.1 to 1.3). Lilly announced the BPH approvals on October 6, 2011 (Eli Lilly news release). The BPH approval covers one specific way of taking it, which the label and your prescriber set; our page on daily vs on-demand tadalafil explains how the two approaches differ, and our main guide to what tadalafil is and how it works covers the rest.
Status: FDA-approved prescription medicine for ED. Source: Cialis prescribing information (Eli Lilly), DailyMed, checked 2026-10-17.
The label is open about what is not known: the same enzyme block that acts in the penis is also seen in the smooth muscle of the prostate, the bladder and their blood supply, but “the mechanism for reducing BPH symptoms has not been established” (section 12.1). It also sets one limit. When tadalafil is started together with finasteride for BPH, the label recommends that use for up to 26 weeks, because the extra benefit shrank between week 4 and week 26 and “the incremental benefit of CIALIS beyond 26 weeks is unknown” (section 1.4).
What did the BPH trials show?
In two 12-week trials in men with moderate to severe BPH symptoms (average age about 63), tadalafil improved the International Prostate Symptom Score (IPSS) significantly more than placebo. The IPSS runs from 0 to 35, with higher scores meaning worse symptoms. Urine flow rate rose in both groups, with no significant difference between them (Cialis label, section 14.3).
| Trial (Cialis label, section 14) | Who took part | Result on the label |
|---|---|---|
| Study J, BPH | Men with BPH symptoms | IPSS fell 4.8 points on tadalafil against 2.2 on placebo at 12 weeks |
| Study K, BPH | Men with BPH symptoms | IPSS fell 5.6 points against 3.6 on placebo at 12 weeks |
| ED and BPH together | 606 men with both conditions | IPSS fell 6.1 against 3.8; erectile function score rose 6.5 against 1.9 at 12 weeks |
| Started with finasteride | 696 men with an enlarged prostate | Better IPSS than finasteride plus placebo at 12 weeks; the gap narrowed from 1.7 points at week 4 to 1.0 at week 26 |
In the trial of men with both conditions, a diary measure of maintaining an erection (SEP3) rose from 43% to 72% on tadalafil, against 36% to 48% on placebo (section 14.4). These are group averages from trials of a few months, not a prediction for any one man, and the ED guideline reminds readers that PDE5 inhibitors “only mitigate symptoms rather than curing the underlying condition” (AUA Erectile Dysfunction Guideline). That guideline also reports that sildenafil and tadalafil appear to work similarly for ED in men with BPH symptoms, and that no studies of vardenafil or avanafil focused on this group. Our side-by-side comparison of ED pills covers the four medicines more broadly.
In the three placebo-controlled trials (two in men with BPH, one in men with ED and BPH), the side effects reported more often on tadalafil included headache (4.1% against 2.3%), indigestion, back pain, nose and throat inflammation (nasopharyngitis), diarrhea, limb pain, muscle aches and dizziness; 3.6% of men on tadalafil stopped because of side effects, against 1.6% on placebo (Cialis label, section 6.1).
Why does the Cialis label warn about alpha-blockers?
Because both kinds of medicine lower blood pressure, and together the drop can be larger. The label explains that PDE5 inhibitors and alpha-blockers “are both vasodilators with blood-pressure-lowering effects,” that the effect may add up, and that in some men the combination “can lower blood pressure significantly,” which may lead to fainting (Cialis label, section 5.6). Its studies tested tadalafil with three alpha-blockers used for BPH: doxazosin, tamsulosin and alfuzosin (section 7.1).
The label treats the two uses differently:
- For BPH, tadalafil is not recommended together with an alpha-blocker, because the combination “has not been adequately studied” for BPH and because of the risk of lowering blood pressure. The label also says men on an alpha-blocker for BPH should stop it before starting tadalafil for BPH, a change the prescriber manages.
- For ED, the label advises caution rather than a ban: a man should be stable on his alpha-blocker before a PDE5 inhibitor is added, and the prescriber starts low. Other blood pressure medicines and substantial alcohol can also add to the effect.
Never adjust these on your own; tell every prescriber about every medicine you take. Nitrates are a separate and stricter matter: the label lists tadalafil with any form of organic nitrate as a contraindication (section 4.1), which our page on nitrates and ED medications explains. The full list of interactions is on our tadalafil drug interactions page.
Can BPH surgery or procedures affect erections?
They can. NIDDK lists “sexual problems, including ED, retrograde ejaculation, and infertility” among the possible complications of BPH surgery, which can include transurethral resection, laser surgery, electrovaporization or robotic surgery. It also describes newer minimally invasive options, such as water vapor therapy and prostatic urethral lift (NIDDK, Enlarged Prostate (BPH)). The 2026 AUA BPH guideline includes a section on sexual function after procedures specifically to support counseling and the choice of procedure (Goueli et al., J Urol 2026, Part III). If you value erectile or ejaculatory function, say so before any procedure is chosen. Our page on ED after prostate treatment covers surgery and radiation for both BPH and prostate cancer, and the treatments used afterward.
Should urinary symptoms be checked before treating ED?
Yes, the AUA ED guideline, the Cialis label and NIDDK all point that way. The ED guideline says that because BPH/LUTS are commonly comorbid with ED and detected at the same time, “appropriate evaluation and therapy for these conditions should be considered” (AUA Erectile Dysfunction Guideline). The Cialis label says evaluation of ED and BPH “should include an appropriate medical assessment to identify potential underlying causes,” and that before treating BPH, other urological conditions that cause similar symptoms should be considered because “prostate cancer and BPH may coexist” (Cialis label, sections 5 and 5.14). NIDDK lists the exams and tests a clinician may use for BPH, such as a digital rectal exam, urinalysis and a PSA blood test, and notes that some cold and cough medicines, tranquilizers, antidepressants and diuretics can make urinary symptoms worse (NIDDK, Enlarged Prostate (BPH)). Our guide to how ED is diagnosed covers the ED side of the same visit.
When to talk to a clinician
See a health care professional about any new urinary symptoms or changes in erections, and mention both, since they often travel together. Bring a list of every medicine you take, including alpha-blockers, finasteride or dutasteride, blood pressure medicines and anything bought over the counter. NIDDK says to get care right away if you cannot urinate at all, have blood in your urine, have painful, urgent urination with fever and chills, or have severe pain in your lower belly. An erection lasting more than 4 hours needs emergency care; see our page on priapism.
The bottom line
An enlarged prostate and ED are linked through shared risk factors, through the urinary symptoms themselves, and through some of the medicines and procedures used for BPH. Finasteride and dutasteride list impotence, lower libido and ejaculation problems, mostly early in treatment, and the tamsulosin label lists ejaculation problems. Tadalafil, an ED medicine, is also FDA-approved for BPH symptoms, but its label advises against pairing it with an alpha-blocker for BPH because of the blood pressure risk. A clinician who knows both conditions and your full medicine list is the right person to weigh the options, and our guide to talking to a doctor about ED can help you start that conversation.
Sources
Every clinical statement on this page traces to a primary or guideline source:
- NIH NIDDK, Enlarged Prostate (Benign Prostatic Hyperplasia) (last reviewed June 2024): definition; 5% to 6% of men 40 to 64 and 29% to 33% of men 65 and older; ED among conditions that make BPH more likely; symptoms and medicines that can worsen them; tests; alpha-blockers, 5-ARIs and PDE5 inhibitors; combination therapy; minimally invasive therapies; ED, retrograde ejaculation and infertility among surgical complications; when to get care right away.
- NIH NIDDK, Symptoms & Causes of Erectile Dysfunction (last reviewed October 2024): enlarged prostate among the conditions that can lead to ED.
- NIH NIDDK, Treatment for Erectile Dysfunction (last reviewed October 2024): medicine review; do not stop any medicine on your own.
- American Urological Association, Erectile Dysfunction Guideline: LUTS/BPH in up to 72% of men with ED; independent risk factors with shared risk factors; similar efficacy of sildenafil and tadalafil in men with BPH/LUTS and ED; evaluation of BPH/LUTS should be considered in men with ED; PDE5 inhibitors mitigate rather than cure.
- American Urological Association, Management of Lower Urinary Tract Symptoms Attributed to BPH: AUA Guideline (2026): bothersome symptoms drive treatment; shared decision-making.
- Goueli R, et al. Management of LUTS Attributed to BPH: AUA Guideline (2026) Part III: Procedural/Surgical Management (J Urol, 2026): sexual function section included to support counseling and procedure selection.
- Rosen R, et al. Lower urinary tract symptoms and male sexual dysfunction: the Multinational Survey of the Aging Male (MSAM-7) (Eur Urol, 2003): 12,815 men aged 50 to 80; sexual problems related to age and LUTS severity independent of comorbidities; LUTS as independent risk factors.
- CIALIS (tadalafil) prescribing information, Eli Lilly, DailyMed (label effective June 2026): sections 1.1 to 1.4 (indications and limitation of use with finasteride); 5 and 5.14 (evaluation and other urological conditions); 5.6 and 7.1 (alpha-blockers and blood pressure); 6.1 (BPH trial side effects); 12.1 (mechanism in BPH not established); 14.3 and 14.4 (BPH and ED/BPH trials).
- PROSCAR (finasteride) prescribing information, Organon, DailyMed (label effective March 2026): PLESS sexual side effects by year; MTOPS rates for placebo, doxazosin, finasteride and the combination, with abnormal ejaculation on the combination comparable to the sum of the single-drug rates; postmarketing reports of persistent sexual effects.
- AVODART (dutasteride) prescribing information, DailyMed (label effective March 2025): sexual side effects by time of onset; possible persistence after stopping.
- JALYN (dutasteride and tamsulosin) prescribing information, DailyMed (label effective March 2026): ejaculation disorders 11% on the combination against 2% and 4% on each alone; abnormal ejaculation with tamsulosin; priapism with alpha-blockers.
- Eli Lilly news release, October 6, 2011: FDA approval of Cialis for BPH symptoms and for ED with BPH symptoms.
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