In this post, I’ll explain everything you need to know about pumpkin seed oil and overactive bladder (OAB). The first thing to keep in mind is that this is still a fairly small field, with not a lot of research done compared to other more well-studied diseases and medications that we’ve heard a lot about. It’s important to remember that science is always being updated, improved, and reviewed to reflect new findings; you’ll see below that this definitely applies to the world of pumpkin seed oil.

What you need to know about pumpkins 

The type of pumpkin that’s been most well-studied in the context of bladder/urinary issue treatments is Cucurbita pepo. It has a lot of subspecies, and comes in many shapes and colors. These subspecies include your traditional “Halloween” pumpkin grown in the Americas, as well as the yellow summer squash, zucchini, and other varieties.¹

Types of bladder issues and what this post will cover

Bladder issues can largely be put into 2 categories: incontinence (leaking) and OAB (urgency).

Incontinence is usually seen in two forms, stress incontinence or overflow incontinence. They’re essentially both characterized by involuntary, abnormal urine loss.² Women tend to experience stress incontinence more, and it’s due to physical stresses, such as exercise, jumping, and even sneezing. Stress incontinence is the most common type of incontinence, and it is usually in the form of drops or small dribbles.³ Women experience stress incontinence as they age, usually via menopausal bladder sphincter shrinkage. Overflow incontinence happens when the body produces more urine than the bladder can hold, and this leads to constant dribbling and leakage. This is most often seen in men with prostate issues, like benign prostatic hyperplasia (BPH), which affects 60% of men over 50.⁴ BPH leads to nocturia and can lead to even worse conditions due to lack of sleep. There are other types of incontinence, but I won’t get into it here.

On the other hand, OAB is more about the urgency and constant need to urinate, leading to higher urinary frequency. A lot of things can cause OAB, such as neurological issues, weak pelvic floor, hormone changes, UTI, and medications. Leakage isn’t necessarily a part of OAB, although some folks with OAB accidentally leak because the urge is so strong.⁵

This post is going to focus on OAB, rather than incontinence, even though some of the studies I looked at included measurements related to incontinence. I made sure to focus solely on figuring out how OAB symptoms (things like urgency, # of urinations at night and day) are affected by ingestion of pumpkin seed oil.

Study results

Many studies in women have shown that the extracts from pumpkin seeds, when combined with other ingredients such as soy, appear effective at lowering the frequency of urination. Two different studies, one studying just postmenopausal women and the other study covering a wider age range, using a mixture of pumpkin seed extract and soybean germ extract, found that taking the mixture regularly for 6-8 weeks significantly decreased the number of incontinent events and urinations during day and night.^6,7 Another study used a mixture of Curcubita pepo (pumpkin) seed oil, Rhus aromatica (fragrant sumac) bark extract, and Humulus lupulus (hop) cone extract. This study followed a large number of women from a wide age range, and found that urination frequency, leakages, and overactive bladder-related quality of life measures were significantly improved after 1 to 12 weeks, with the number of women who reported improvements significantly increasing over the 12 weeks.⁸ 

Some studies have been performed in men as well. One study used the water soluble portion of Curcubita pepo and had their participants, with an average age of 62 years and having already developed BPH, ingest 500mg of it every night for 3 months. IPSS (International Prostate Symptom Score) and bladder diary were the two ways that changes were recorded. The authors found that IPSS scores (which represent measurements for nocturia, urgency, urinating more often than every 2 hours, etc.) that represent the symptoms and nocturia were significantly decreased.⁹ Another study looked at pollakiuria symptoms in elderly men, all > 65 years of age, and if a mix of EFLA940 pumpkin seed extract and soybean germ extract helped their symptoms over the 6 week study. There were two groups – those that combined the EFLA940 + soy with their pollakiuria drug, and those that only took the EFLA940 + soy. The study found that by week 2, there was a significant decrease in nocturnal urination in the EFLA940 + soy group, but not in the group that also took a pollakiuria drug with it. In addition, sleep satisfaction significantly increased for both groups at 6 weeks.¹⁰ This study was odd, because pollakiuria is defined as frequent daytime urination in children from 3-5 years old and in some teens, not elderly folks.^11,12

Nishimura et al. studied the pumpkin seed oil extract from a Japanese pumpkin called Cucurbita maxima, which isn’t the type that’s studied in the work above. The study required the participants to eat 10 grams of pumpkin seed oil extract every day and found that after 12 weeks, the average OABSS (Overactive Bladder Symptom Score) was significantly lower.¹³

These results might sound great at first, but an important thing to realize when you read these results is that these studies are not perfect by any means. Sample sizes weren’t very large for some of the studies, all of them used some form of self-reporting as part of data collection and therefore had extremely biased results, placebos weren’t used, most of the populations studied were of older age, and the participants knew what the study was about and knew the purpose of the tablets they were taking. 

In order to be more convinced that pumpkin seed oil is helpful in alleviating symptoms of OAB, we really need to see double-blind, randomized studies with a placebo, and they have to take place over longer than 12 weeks.

Conclusion

There are a handful of studies that look at the effects of pumpkin seed oil and its effects on OAB symptoms. Some of them also study incontinence symptoms related to BPH. Overall, they report that pumpkin seed oil can help alleviate symptoms of OAB and increase quality of life. However, these studies aren’t well-designed, because self-reported symptom surveys and bladder diaries are very subjective – especially when the participants know they’re taking something for their bladder! In addition, the sample sizes are small, placebos aren’t used, and the studies aren’t long-term.

This area of study needs much more work. It’d be great if researchers figure out ways to quantify change in urinary frequency that’s not so subjective and can be completely blinded. A few dozen people who have the luxury to take time out of their lives to keep a diary of symptoms and check in with the researchers are not going to accurately represent the entire population.

A lot of pumpkin seed oil supplements come up when you do a quick Google search to see what’s out there. Many of them don’t mention the specific type of pumpkin that the oil is from. Many only say “pumpkin seed oil”. It’s hard to be sure what types of pumpkins the oils in those supplements are extracted from. You can definitely find some that specifically mention Curcubita pepo, such as Azo Bladder Control, Puritan’s Pride, and Nature in a Bottle. I wouldn’t go out and purchase a ton of it based on these studies alone, because of the drawbacks I mentioned above.

You should always listen to a medical professional, in this case a urologist, and inform yourself of what your treatment options are before buying into fads like this.