About one in five adults worldwide deals with overactive bladder symptoms, and that number keeps climbing. If you’re one of them, you’ve probably tried cutting back on coffee and timing your bathroom trips. Maybe you’ve done pelvic floor exercises too. Maybe you’ve been prescribed medication that helped some but came with dry mouth or constipation.

So it makes sense that roughly 75% of people with OAB have tried some form of complementary medicine 1. The appeal is obvious: something that might help without the side effects of prescription drugs.

I want to be upfront here. The supplement evidence for OAB is not as strong as what we have for standard medications like mirabegron or solifenacin. Some of these supplements have decent clinical trials behind them. Others are still mostly backed by animal research or traditional use. I’ll be clear about where each one stands.

How Overactive Bladder Works (and Where Supplements Might Fit)

OAB happens when the detrusor muscle in the bladder contracts involuntarily, creating that sudden urgency even when the bladder isn’t full. This can lead to frequent urination, urge incontinence, and nocturia (waking up at night to pee).

Several biological pathways are involved, from calcium signalling in the muscle to nerve sensitivity and inflammation. Different supplements target different parts of this puzzle, which is why some work better for certain people than others.

For a full overview of the condition, see our pages on overactive bladder in women and overactive bladder in men.

1. Pumpkin Seed Extract

Pumpkin seed extract is probably the supplement with the most direct evidence for OAB specifically. A randomised, double-blind, placebo-controlled trial with 120 participants tested a combination of pumpkin seed and soy germ extracts over 12 weeks. The treatment group saw significant reductions in urination frequency, urgency, incontinence episodes, and nighttime bathroom trips compared to baseline 2.

A separate open-label study of 45 people taking 10 grams of pumpkin seed oil daily for 12 weeks also showed improvements on the Overactive Bladder Symptom Score at both 6 and 12 weeks. No significant side effects were reported in either study.

The active compounds appear to be the phytosterols and fatty acids in the seeds, which may influence bladder muscle function. Pumpkin seed has also been studied for benign prostatic hyperplasia, where it shows similar benefits for urinary symptoms.

My take: this is one of the more promising options on this list. The evidence isn’t overwhelming, but the safety profile is good and the mechanism is plausible. If I were going to try one supplement for OAB, this would probably be it. For more on pumpkin seed oil specifically, see our detailed article.

2. Magnesium

Magnesium works as a natural calcium antagonist, meaning it can help relax smooth muscle, including the detrusor muscle in the bladder. The logic is straightforward: if involuntary muscle contractions drive OAB symptoms, then something that calms muscle activity might help.

A double-blind, placebo-controlled study of 40 women found that 55% of those taking magnesium hydroxide reported improvement in urgency and frequency, compared to 25% on placebo 3. The urodynamic measurements didn’t reach statistical significance, but the subjective improvement was notable.

More recently, analysis of data from over 28,000 US adults found that each 1-point increase in magnesium depletion was linked to 9% higher odds of having OAB 4. This doesn’t prove magnesium supplementation helps, but it does suggest that being low on magnesium is associated with bladder overactivity.

Worth noting: magnesium can cause diarrhea at higher doses, which is not ideal when you’re already dealing with frequent bathroom trips. Start with a lower dose (200 mg of elemental magnesium) and work up. Forms like magnesium glycinate tend to be gentler on the stomach than magnesium oxide. If you have kidney problems, check with your doctor first, as impaired kidneys can’t clear excess magnesium properly.

For a broader look at magnesium’s effects, see our magnesium article.

3. Vitamin D

The connection between vitamin D and bladder function has gained a lot of research attention in recent years. A 2024 meta-analysis of 13 studies found that people with vitamin D deficiency had 4.46 times the odds of having OAB compared to those with adequate levels. Supplementation reduced urinary incontinence risk by an estimated 66% 5.

That’s a striking number. But context matters. A randomised trial of 90 postmenopausal women (all with low vitamin D) found that 50,000 IU weekly for 8 weeks significantly reduced incontinence severity, nocturia frequency, and daily life disruption 6. However, a much larger trial (the VITAL study with over 11,000 men) found no overall benefit, except in the subgroup who were already vitamin D deficient 7.

So here’s the honest read: if you’re vitamin D deficient, supplementation may genuinely help your bladder symptoms. If your levels are already normal, adding more vitamin D probably won’t make a difference. The smart move is to get your vitamin D level tested first.

Vitamin D receptors are found in bladder smooth muscle and the pelvic floor, which gives a biological explanation for why deficiency might contribute to bladder problems. For more details, check our articles on vitamin D effects and how to supplement vitamin D.

4. Quercetin

Quercetin is a flavonoid found in onions, apples, and berries. Most of the bladder research focuses on interstitial cystitis and painful bladder syndrome rather than OAB specifically, but there’s meaningful overlap in symptoms.

An open-label trial of 22 patients with interstitial cystitis found that 500 mg of quercetin twice daily for 4 weeks cut symptom scores roughly in half and reduced pain from 8.2 to 3.5 on a 10-point scale 8. A larger study of 252 patients using a quercetin-containing combination (with glucosamine and chondroitin sulfate) found about a 50% reduction in symptom severity over 11 months 9.

Quercetin appears to work by stabilising mast cells and reducing inflammation in the bladder wall. If your OAB symptoms include bladder pain or burning alongside urgency, quercetin might be particularly worth considering.

Limitations: no placebo-controlled trials for OAB specifically, and the larger study used a combination product, so quercetin’s individual contribution is unclear. For a deeper look, see our quercetin article.

5. Beta-Sitosterol

Beta-sitosterol is a plant sterol found in saw palmetto, pumpkin seeds, and nuts like almonds and pecans. The strongest evidence is for men with BPH-related urinary symptoms rather than OAB per se, but many of those symptoms (urgency, frequency, nocturia, weak stream) overlap significantly.

A systematic review of 4 randomised controlled trials involving 519 men found that beta-sitosterol improved symptom scores by an average of 4.9 points and increased peak urinary flow by about 3.9 mL per second compared to placebo 10. A separate multicentre trial of 177 men confirmed these findings over 6 months of treatment 11.

The catch: beta-sitosterol didn’t reduce prostate size in any of these studies. It seems to improve symptoms through a different mechanism, possibly by reducing inflammation rather than shrinking tissue. This actually makes it potentially relevant beyond BPH, since the anti-inflammatory effect could benefit bladder function more broadly.

Side effects in the trials were minimal, with dropout rates under 8%. If you’re a man with lower urinary tract symptoms that include OAB-like urgency and frequency, beta-sitosterol has a reasonable evidence base.

6. Gosha-jinki-gan

This is a traditional Japanese herbal formula (called Kampo medicine) containing 10 herbs, including processed aconite root, cinnamon bark, and rehmannia root. It’s widely prescribed by urologists in Japan for OAB.

A study of 44 women with OAB found a 53% response rate after treatment with 7.5 grams daily, with significant decreases in urgency, frequency, and nocturia scores 12. A separate trial in 30 men showed similar improvements over 6 weeks 13.

This formula appears to work partly through effects on nerve signalling in the bladder, though the exact mechanism isn’t fully understood given the number of active compounds involved.

The downsides: it contains processed aconite, which is toxic when raw and must be properly processed. About 9% of patients in the women’s study experienced mild side effects like diarrhea and nausea. You can’t easily source this outside of Japan, and self-prescribing a 10-herb formula without guidance seems unwise. If you do want to try it, work with a practitioner experienced in Kampo medicine.

7. Horsetail Extract (as Part of Urox)

Horsetail extract on its own has limited evidence for OAB, but a combination product called Urox (containing horsetail, Crataeva nurvala bark, and Lindera aggregata root) showed promising results in a Phase 2 randomised controlled trial.

The study of 150 participants over 8 weeks found that the Urox group averaged 7.69 bathroom trips per day versus 10.95 for placebo. Nighttime trips dropped to 2.16 versus 3.14 on placebo. Urgency, incontinence, and quality of life all improved significantly 14.

Additional research found that horsetail extract stimulated production of Tamm-Horsfall protein, which has a protective role in the urinary tract and helps prevent bacteria from sticking to bladder cells 15.

The honest caveat: since Urox is a combination product, we can’t say how much horsetail alone contributes. Also, horsetail contains thiaminase, which can deplete vitamin B1 with long-term use. The general recommendation in herbal medicine references is not to use horsetail continuously for more than two months without a break.

Supplements I Looked At But Didn’t Include

A few others come up frequently online but don’t have enough evidence to recommend:

Corn silk extract has centuries of traditional use for bladder complaints, but the one human study (38 volunteers) found no significant effect on urine output 16. Animal studies show diuretic effects, but that hasn’t translated to human data yet.

Buchu leaf was popular in 19th-century America for urinary conditions but has zero clinical trials for OAB. A 2022 review concluded that health claims for buchu “need to be substantiated by randomized, double-blind and placebo-controlled studies” 17. Maybe in the future, but not yet.

When to See a Doctor

Supplements should not be your first or only approach to OAB. See a doctor if:

Your symptoms are getting worse despite lifestyle changes
You’re experiencing blood in your urine
You have pain with urination (dysuria)
Urgency is severe enough that you regularly don’t make it to the bathroom
Nighttime urination is disrupting your sleep and daily functioning
You’re considering combining supplements with prescription OAB medication (interactions are possible)

OAB can sometimes be a sign of other conditions, including neurogenic bladder, bladder stones, or in rare cases bladder cancer. Getting a proper diagnosis matters.

Frequently Asked Questions

What is the best natural supplement for overactive bladder?

Based on current evidence, pumpkin seed extract has the most direct research for OAB specifically, with a double-blind trial showing reduced frequency and urgency over 12 weeks. Magnesium and vitamin D also have supporting data, especially if you’re deficient. There’s no single “best” option since different supplements work through different mechanisms.

Can magnesium really help with bladder control?

There’s reasonable evidence that it can. A placebo-controlled study found 55% of women taking magnesium reported improved urgency, and population data links magnesium depletion with higher OAB risk 3. Magnesium relaxes smooth muscle, including the detrusor muscle responsible for bladder spasms. It works best if you’re actually low on magnesium to begin with.

Is it safe to take supplements for overactive bladder alongside prescription medication?

Some combinations carry interaction risks. Magnesium can interfere with certain antibiotics and bisphosphonates. Quercetin may interact with blood thinners and fluoroquinolone antibiotics. Beta-sitosterol and pumpkin seed are generally well tolerated alongside medications. Always tell your doctor what supplements you’re taking, especially if you’re on OAB medications like oxybutynin or mirabegron.

How long do supplements take to work for overactive bladder?

Most studies showing positive results ran for 8 to 12 weeks. Pumpkin seed extract showed some improvement at 6 weeks but better results at 12 weeks. Vitamin D supplementation in one trial showed benefits after 8 weeks 6. If you don’t notice any change after 3 months, a particular supplement likely isn’t going to help you.

Does vitamin D deficiency cause overactive bladder?

Deficiency doesn’t directly “cause” OAB, but research shows a strong association. A meta-analysis found that vitamin D deficient people had over 4 times the odds of having OAB 5. Vitamin D receptors exist in bladder muscle and pelvic floor tissue, and correcting a deficiency has been shown to improve symptoms in clinical trials.

Putting It All Together

Here’s my honest ranking of these supplements by strength of evidence:

Pumpkin seed extract has the most direct OAB evidence from randomised trials
Vitamin D has strong evidence, but mainly benefits those who are deficient
Magnesium has plausible mechanisms and supporting data, though the key RCT was small
Beta-sitosterol has strong evidence for men with BPH-related urinary symptoms
Quercetin shows promise for bladder pain and IC, with potential OAB crossover
Gosha-jinki-gan is effective in Japanese studies but hard to access and self-prescribe
Horsetail (Urox) performed well in one trial but only as part of a combination product

None of these will fix OAB on their own. The economic burden of OAB in the US alone is estimated at nearly $66 billion annually 18, which tells you this is a condition that resists easy solutions. Supplements work best as one part of a broader approach that includes lifestyle changes, pelvic floor exercises, and medical treatment where needed.

If you want to try a supplement, pick one, give it 8 to 12 weeks, and track your symptoms. A bladder diary (recording how often you go, how much you void, and urgency episodes) will tell you whether something is actually working better than guessing.

References

Chughtai B et al. Use of herbal supplements for overactive bladder. Reviews in Urology (2013)
Nishimura M et al. Pumpkin seed oil improves urinary disorder in human overactive bladder. J Tradit Complement Med (2014)
Gordon D et al. Magnesium hydroxide for treatment of sensory urgency and detrusor instability. BJOG (1998)
Association between magnesium depletion score and overactive bladder among the US population. NHANES analysis (2025)
Zhang Q et al. Vitamin D levels and the risk of overactive bladder: a systematic review and meta-analysis. Nutrition Reviews (2024)
Arjmand M et al. The effect of vitamin D on urgent urinary incontinence in postmenopausal women. Int Urogynecol J (2023)
Markland AD et al. Effect of vitamin D supplementation on OAB and UI symptoms in older men. J Urol (2023)
Katske F et al. Treatment of interstitial cystitis with a quercetin supplement. Tech Urol (2001)
Theoharides TC et al. Treatment of refractory IC/PBS with CystoProtek. Can J Urol (2008)
Wilt TJ et al. Beta-sitosterol for the treatment of BPH: a systematic review. BJU Int (1999)
Klippel KF et al. Beta-sitosterol for the treatment of BPH: multicentre RCT. Br J Urol (1997)
Kajiwara M, Mutaguchi K. Clinical efficacy of gosha-jinki-gan in females with OAB. Hinyokika Kiyo (2008)
Effect of Chinese herbal medicine on overactive bladder. (2008)
Schoendorfer N et al. Urox in treatment of symptoms of OAB and urinary incontinence. BMC Complement Altern Med (2018)
Equisetum arvense stimulates Tamm-Horsfall protein secretion. (2022)
Corn silk in healthcare: a phytochemical and pharmacological review. Molecules (2018)
Brendler T, Abdel-Tawab M. Buchu: rightfully forgotten or underutilized? Front Pharmacol (2022)
The burden of OAB on US public health. Urology (2016)