Pumpkin seed (Cucurbita pepo) has been traditionally used in various cultures for urinary and bladder health, particularly for symptoms associated with irritable or overactive bladder. In recent years, this use has gained some scientific attention. Several small clinical studies and reviews suggest that pumpkin seed extract may help reduce symptoms such as urinary frequency, urgency, and nocturia, especially in cases of overactive bladder (OAB) and benign prostatic hyperplasia (BPH) in men.

One randomized, placebo-controlled study in 2014 found that participants taking pumpkin seed oil extract experienced significant improvements in OAB symptoms compared to placebo. The proposed mechanisms include the inhibition of 5-alpha reductase (which affects prostate growth) and modulation of bladder muscle activity, possibly due to the phytosterols, lignans, and fatty acids found in pumpkin seeds.

However, the overall quality of evidence remains moderate to low. Most studies to date have been small, of short duration, and sometimes industry-sponsored. Systematic reviews note that while the results are promising, larger, well-designed trials are needed to confirm efficacy and safety for bladder irritability specifically. Thus, while there is some scientific validation for pumpkin seed in managing irritable bladder symptoms, the evidence is not robust enough to merit a high rating.