Viagra and other PDE5 inhibitors can help with some symptoms of an enlarged prostate (benign prostatic hyperplasia, or BPH), and the related medicine tadalafil (Cialis) is actually approved for it. While Viagra's main use is erectile dysfunction, research shows it can ease lower urinary tract symptoms in some men — which is useful, since ED and BPH often occur together.
Can Viagra treat an enlarged prostate?
Viagra, also known as sildenafil citrate, is best known for improving erectile dysfunction by increasing blood flow to the penis. Benign prostatic hyperplasia (BPH) is a non-cancerous enlargement of the prostate that causes lower urinary tract symptoms (LUTS) such as a weak stream, frequent urination and getting up at night to urinate. Because the smooth muscle of the prostate and bladder responds to the same relaxing effect that PDE5 inhibitors produce, these medicines can ease some BPH symptoms, even though Viagra itself is licensed mainly for ED.
The ED–BPH connection
ED and BPH frequently go hand in hand, partly because both become more common with age and share underlying factors. A man being treated for one often has the other. This overlap is one reason researchers have studied whether ED medicines can help with prostate symptoms. A Northwestern University study, among others, looked at how Viagra affects LUTS and erectile function together, finding benefits for some men. Treating both at once can therefore be appealing, much as the link explored in prostatitis and ED.
What the evidence shows
Studies suggest that sildenafil can improve lower urinary tract symptoms, including reducing nocturia (waking to urinate) in some patients with LUTS/BPH. Different dosages have been compared, and PDE5 inhibitors appear to offer a modest benefit on urinary symptoms alongside their effect on erections. That said, tadalafil — the active ingredient in Cialis — is the PDE5 inhibitor specifically approved for BPH, often at a low daily dose, and is more commonly used for this purpose than Viagra. The doctor decides which medicine and dose suit your situation.
Talk to your doctor
If you have both ED and an enlarged prostate, discuss it with your doctor rather than self-treating. They can assess your symptoms, confirm the diagnosis and decide whether a PDE5 inhibitor — and which one — is appropriate, alongside other BPH treatments. The same safety rules apply as for any ED medicine, including never combining it with nitrates, as noted in our guidance on ED medicines and procedures. For related prostate concerns, see Viagra and Peyronie's disease.
Daily tadalafil for both problems
For men who have both an enlarged prostate and erectile dysfunction, one practical option is low-dose daily tadalafil, which is approved to treat both conditions at once. Taken every day rather than before sex, it keeps a steady level of the medicine in the body, easing urinary symptoms while also supporting erections. This 'two birds, one stone' approach can simplify treatment and is one reason tadalafil, rather than Viagra, is often chosen when BPH is part of the picture. As always, whether it suits you depends on your overall health and other medicines, so the decision belongs with a doctor who can weigh the benefits against any cautions and rule out interactions such as those with nitrates.
For more on prostate health and ED, return to our erectile dysfunction and Viagra hub.