Does Tadalafil Cause Increased Urination?
No, tadalafil does not cause increased urination as a side effect; in fact, it is specifically approved to treat urinary frequency and other lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), and clinical evidence demonstrates it actually reduces urinary frequency rather than increasing it.
FDA-Approved Indication for Urinary Symptoms
The FDA label explicitly states that tadalafil is approved for treating "men with symptoms of benign prostatic hyperplasia (BPH)" and "men with both ED and BPH" 1. BPH causes urinary symptoms including frequency, urgency, and nocturia—and tadalafil is prescribed specifically to improve these symptoms, not cause them.
Clinical Evidence Shows Reduction in Urinary Frequency
BPH Studies
In two pivotal BPH trials involving 748 patients, tadalafil 5 mg daily significantly improved total International Prostate Symptom Score (IPSS) compared to placebo, with improvements starting at 4 weeks and maintained through 12 weeks 1. The IPSS specifically measures irritative symptoms including urinary frequency and urgency—and tadalafil improved these parameters.
Overactive Bladder Research
A randomized controlled trial in 96 women with overactive bladder found that daily 5 mg tadalafil significantly decreased frequency, incontinence, and urgency episodes compared to placebo, with improvements maintained 3 months post-treatment 2. This directly contradicts the notion that tadalafil increases urination.
Nocturia (Nighttime Urination)
Pooled data from four registrational studies (N=1,500) showed tadalafil 5 mg reduced nighttime voiding frequency (nocturia) with a statistically significant treatment difference of -0.2 voids per night versus placebo (p=0.002) 3. While the clinical significance was modest, the direction of effect is clear: reduction, not increase.
Mechanism of Action on Bladder Function
Urodynamic studies in 71 treatment-naïve BPH patients demonstrated that tadalafil 5 mg daily:
- Increased maximum bladder capacity by approximately 35 mL (p<0.001)
- Eliminated detrusor overactivity in 39.5% of patients who had it at baseline
- Improved both storage and voiding function objectively 4
These findings indicate tadalafil stabilizes bladder function and increases bladder capacity, which would decrease—not increase—urinary frequency.
Actual Side Effects of Tadalafil
The FDA label and AUA guidelines clearly list the most common adverse events with tadalafil: dyspepsia, headache, flushing, back pain, nasal congestion, myalgia, visual disturbance, and dizziness 5, 1. Increased urination is not listed as a recognized side effect.
Clinical Bottom Line
If a patient reports increased urination while taking tadalafil, consider alternative explanations:
- Coincidental timing with worsening BPH or other urological conditions
- Increased fluid intake (patients may drink more water when taking medications)
- Unrelated conditions such as diabetes, urinary tract infection, or diuretic use
- Nocturnal polyuria from other causes (heart failure, sleep apnea, excessive evening fluid intake)
The evidence consistently demonstrates that tadalafil improves urinary frequency in patients with BPH and overactive bladder symptoms. It does not cause increased urination as a medication side effect.