The Research Behind CYSTUROL

The research behind Sunn Biolabs formulations

Evidence-based ingredients. Pharmaceutical-grade manufacturing. Reviewed by urologists.

At Sunn Biolabs, every formulation begins with peer-reviewed evidence. Our approach isn't to assemble whatever ingredients are trending — it's to build formulas around actives that have been studied in the populations we serve, manufacture them to pharmaceutical-grade standards, and refine them with input from practicing urologists. This page summarizes the published research behind our bladder-health formula CYSTUROL, designed for women (and the men often overlooked) living with interstitial cystitis / bladder pain syndrome, with links to the original studies on PubMed.

These statements have not been evaluated by the Food and Drug Administration. CYSTUROL is a dietary supplement and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any new supplement.

BUILT ON SCIENCE  |  CLINICALLY INFORMED  |  UNCOMPROMISINGLY CLEAN

Cleveland Clinic  ·  UCLA  ·  Cedars-Sinai  ·  Queen's University  ·  Providence  ·  Keck Medicine of USC

Members of our Medical Advisory Board and formulation consultants hold academic and clinical appointments at these institutions.

ON THIS PAGE

  • About interstitial cystitis / bladder pain syndrome (IC/BPS)
  • The research behind CYSTUROL — ingredient by ingredient
  • What makes CYSTUROL different
  • Part of a multi-modal approach
  • Full references

About IC/BPS

What is interstitial cystitis / bladder pain syndrome, and why is it so hard to treat?

A common condition that is often missed for years

Interstitial cystitis / bladder pain syndrome (IC/BPS) is a chronic bladder and pelvic pain condition characterized by urinary urgency, frequency, nocturia, and pain perceived to be related to the bladder, persisting for six weeks or longer in the absence of infection or other identifiable causes. The RAND Interstitial Cystitis Epidemiology (RICE) study estimated that 2.7% to 6.5% of US adult women — roughly 3 to 8 million women — have symptoms consistent with IC/BPS [1]. A follow-up RICE male study estimated that approximately 2% to 4% of US men have symptoms of IC/BPS as well — a population that is often overlooked because the symptoms overlap with chronic prostatitis, leading to diagnostic delays that frequently stretch beyond four years [2].

Why treatment is so difficult

IC/BPS has a heterogeneous pathophysiology. Disruption of the bladder's glycosaminoglycan (GAG) protective layer allows urinary solutes (particularly potassium) to penetrate the urothelium, triggering inflammation, mast cell degranulation, and nerve sensitization [3]. Bladder tissue from IC patients shows mast cell densities 6- to 8-fold higher than controls in classic IC, with mast cell activation (tryptase, histamine, TNF-α release) central to symptom generation [4][5]. Many patients also experience central sensitization, systemic comorbidities (IBS, fibromyalgia, chronic fatigue), and psychosocial burden — which is why the NIH-funded MAPP Research Network frames IC/BPS and chronic prostatitis together under the "urologic chronic pelvic pain syndromes" (UCPPS) umbrella as a systemic, not purely bladder-local, condition [6].

The standard measure: the O'Leary-Sant Indices

The O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and Problem Index (ICPI), developed and validated in 1997, are the standard outcome measures used in IC/BPS clinical research [7]. The ICSI covers four items (urgency, frequency, nocturia, pain/burning) scored 0–20; the ICPI covers four parallel "problem" items scored 0–16. The ICSI/ICPI has been further validated in larger clinical trials, including studies of pentosan polysulfate (Elmiron), one of the few FDA-approved oral IC therapies [8]. When we cite clinical research on this page, O'Leary-Sant scores are the measure referenced.

The multi-modal approach: AUA 2022 Guideline

The 2022 American Urological Association guideline for IC/BPS is a significant reframing of how IC is managed. It no longer divides treatments into stepwise first- through sixth-line tiers; instead, treatments are categorized as behavioral/non-pharmacologic, oral medications, bladder instillations, procedures, and major surgery, emphasizing individualized, multi-modal care based on patient-specific symptoms and subtypes [9]. The guideline explicitly recognizes IC/BPS as a chronic pain syndrome rather than a primary bladder disease.

CYSTUROL is designed to fit within this multi-modal approach, not to replace it.

The research behind CYSTUROL

What's in the formula, and what's the evidence?

Quercetin (from Quercetin Dihydrate) — the anchor ingredient

Quercetin is a plant bioflavonoid. It is the most-studied ingredient in CYSTUROL and the one with the strongest direct IC/BPS evidence.

The foundational pilot study. In 2001, an open-label pilot study was published of a quercetin-based supplement (500 mg quercetin twice daily for four weeks) in 22 adults with classically documented interstitial cystitis — 17 women and 5 men, with 20 completers. The pilot reported significant improvements across all three parameters assessed: pain, urgency, and frequency, with good tolerability [10]. This small pilot is the first published clinical signal for quercetin in IC/BPS and has shaped the formulation tradition CYSTUROL builds on. Because it was open-label and uncontrolled, we describe it as a pilot study, not as a controlled trial — but it remains the most-cited direct-IC quercetin reference.

Follow-on open-label research. Theoharides and Sant published a 2005 open-label study of a multi-agent natural formula containing quercetin alongside GAG-supporting compounds (chondroitin sulfate, sodium hyaluronate, glucosamine, rutin) in 37 women with treatment-refractory IC. Over six months, O'Leary-Sant Symptom Index scores decreased from 16.3 to 6.9 and Problem Index from 13.1 to 5.4 (both p < 0.05) [11]. A larger 2008 follow-up of 252 IC/PBS patients (227 women, 25 men) reported that the majority of patients experienced symptomatic improvement over 6–12 months with good tolerability [12]. These studies evaluate quercetin-containing formulas rather than quercetin alone, but they are the largest natural-supplement IC series available and establish the formulation family CYSTUROL's approach is rooted in.

The UCPPS bridge. Quercetin has been studied for over two decades in urologic chronic pelvic pain syndromes. Researchers, who led both the original 1999 quercetin trial in chronic prostatitis and the 2001 IC pilot, published a dedicated 2011 review in Urologic Clinics of North America discussing quercetin's mechanism — particularly its mast-cell-stabilizing activity — and its place in the phenotype-directed care of urologic chronic pelvic pain [13]. Because the MAPP Network frames IC/BPS and chronic prostatitis as mechanistically overlapping UCPPS conditions, this body of research is directly relevant to the bladder-focused patient population CYSTUROL serves [6].

Mechanism of action. Beyond the clinical research, quercetin's mechanism aligns closely with the pathophysiology of IC/BPS:

  • A 2012 study in PLoS ONE demonstrated that quercetin is more effective than cromolyn — a pharmaceutical mast cell stabilizer used off-label in IC — at blocking inflammatory mediator release from human mast cells [14]. Because mast cell activation is central to IC symptom generation [4][5], this is a particularly relevant mechanism for CYSTUROL's bladder-focused context.
  • A 2016 review in Nutrients summarized how quercetin modulates inflammatory signaling pathways (NF-κB, MAPK) and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) [15].
  • A 2024 mechanistic study in an IC/BPS rat model reported that quercetin reduced bladder inflammation (MPO, IL-1β, IL-6, TNF-α), alleviated bladder injury, and reduced mast cell degranulation — and identified a hub gene (Lpl) linked to restoration of the bladder's protective GAG layer [16]. This is preclinical research, but it directly connects quercetin to the mast-cell and GAG-layer pathways that define IC.

Bromelain — formulation synergy

Bromelain is a proteolytic (protein-digesting) enzyme derived from pineapple stem. It is included in CYSTUROL for two purposes, both well-documented in the peer-reviewed literature:

Anti-inflammatory support. A 2012 review in Biotechnology Research International summarized bromelain's proteolytic, anti-inflammatory, and anti-edematous properties across multiple therapeutic contexts [17]. A 2004 review of bromelain in osteoarthritis reported that oral bromelain was associated with improvements in pain and swelling across early-phase clinical studies [18].

Absorption of co-administered actives. Quercetin has notoriously low oral bioavailability on its own. Combining quercetin with proteolytic enzymes — specifically bromelain and papain — is the formulation rationale described in the 2003 review in World Journal of Urology for the quercetin-based urologic-pain supplement tradition [19]. This quercetin-plus-enzymes structure is the foundation CYSTUROL builds on, applied to the bladder-focused context.

Papain — digestive-enzyme support

Papain is a proteolytic enzyme from papaya. Like bromelain, it's paired with quercetin in CYSTUROL as part of the proteolytic-enzyme approach to supporting the formulation's overall absorption and anti-inflammatory profile. Papain has traditional use as a digestive enzyme, and clinical work with papaya-derived preparations has shown associations with improvements in gastrointestinal tolerance [20].

We include papain for its role in the quercetin + proteolytic-enzymes formulation family and for its contribution to gastrointestinal tolerance — especially relevant because people living with IC often describe heightened sensitivity to supplements that irritate their systems.

Cranberry Fruit

A note on cranberry in an IC context is warranted. Cranberry has a strong evidence base for supporting urinary tract health, particularly in reducing recurrent urinary tract infections. The 2023 Cochrane systematic review (50 RCTs, 8,857 participants) concluded that cranberry products were associated with a reduced number of symptomatic, culture-verified UTIs in women with recurrent UTIs, in children, and in people susceptible to UTIs following bladder interventions [21]. The proposed mechanism — A-type proanthocyanidins inhibiting adhesion of P-fimbriated E. coli to bladder wall cells — is well-characterized [22].

A note for IC-sensitive bladders. Cranberry juice is commonly identified by the IC community as a dietary trigger due to its acidity. In CYSTUROL, cranberry is included in capsule form as whole-fruit powder rather than juice, contributing to the formula's general urinary tract support profile without exposing sensitive bladders to the acid load commonly associated with cranberry juice products. We include cranberry for its established urinary-tract-health role — not as an IC-symptom-targeted ingredient.

Passion Flower Herb (Passiflora incarnata)

Passion flower has a long traditional use history as a calming nervine and has a modest but consistent modern clinical evidence base for supporting calm and restful sleep. We include it in CYSTUROL for the nervous-system and stress-axis dimension of living with IC — the central-sensitization, sleep-disruption, and anxiety burden that many people with chronic bladder symptoms describe — not as an IC-specific treatment.

Clinical evidence for calm. A 2008 double-blind, placebo-controlled randomized trial of 60 ambulatory surgery patients found that oral Passiflora incarnata (500 mg, 90 minutes pre-procedure) was associated with significantly lower pre-procedure anxiety scores than placebo, without delayed psychomotor recovery [23]. A 2020 systematic review of nine randomized trials reported that the majority of studies described reduced anxiety levels following Passiflora administration, with no adverse effects on memory or psychometric function [24].

Clinical evidence for sleep. A 2011 double-blind crossover trial of Passiflora incarnata herbal tea reported significant improvements in subjective sleep quality compared with placebo tea in healthy adults with mild sleep complaints [25].

Mechanism of action. The mechanism most often cited in modern research is GABAergic — flavonoid constituents (chrysin, apigenin) and related compounds interact with GABA-A receptors to produce calming effects [26]. GABAergic tone is a major modulator of central pain processing and sleep-wake regulation, which is why the calming and sleep-supporting properties of Passiflora are relevant to people whose night-time bladder symptoms disrupt rest.

Valerian Root (Valeriana officinalis)

Valerian root has been used for centuries as a traditional herbal to support restful sleep and ease tension. We include it in CYSTUROL specifically because night-time urinary symptoms disrupt sleep in many people with bladder discomfort, and supporting the sleep dimension is part of what it means to live better with a chronic bladder condition.

Modern meta-analytic evidence. A 2020 systematic review and meta-analysis of 60 studies (n = 6,894) concluded that valerian was associated with improved subjective sleep quality and reduced anxiety, with a favorable safety profile across ages 7–80 [27]. An earlier 2006 meta-analysis of 16 studies (n = 1,093) similarly found that subjective sleep-improvement outcomes favored valerian over placebo (RR 1.8, 95% CI 1.2–2.9) [28]. Variability across earlier trials has been attributed primarily to differences in extract quality — a reason CYSTUROL uses pharmaceutical-grade-manufactured valerian from an identity-verified source.

Mechanism of action. Valerenic acid, the principal active constituent of valerian root, has been identified as a GABA-A receptor modulator — the GABA-A β3 subunit is the in vivo substrate for its anxiolytic effect [29][30]. Like passion flower, valerian's GABAergic mechanism is what supports its calming and sleep-promoting role in the formula.

Wood Betony Leaf (Stachys officinalis)

Wood betony is a classical Western herbal that has been used in European folk medicine for centuries — appearing in Anglo-Saxon leech-books, Culpeper's Complete Herbal, and Byzantine medical manuscripts — traditionally described as a calming herb for nervous tension and headache. We include wood betony in CYSTUROL for its long history of traditional herbal use, not as a clinically studied IC ingredient.

Phytochemistry. The Stachys genus has been characterized phytochemically and contains phenylethanoid glycosides — including a family unique to Stachys officinalis called betonyosides A–F [31] — alongside flavonoids and terpenoids documented in other research for in-vitro antioxidant and anti-inflammatory activity. A 2020 review in Medicines catalogued the genus's traditional uses across Mediterranean, Asian, American, and African herbal systems alongside its constituent chemistry [32].

Wood betony's role in CYSTUROL is traditional-use based. We do not claim it has been clinically studied for IC or for bladder symptoms — no such clinical evidence exists.

What makes CYSTUROL different

How CYSTUROL differs from generic "bladder support" supplements

Digestive enzymes for absorption

Quercetin — CYSTUROL's anchor ingredient — has famously low oral bioavailability when taken on its own. A quercetin capsule without absorption support can leave much of the active unused.

CYSTUROL's formulation addresses this directly by including two proteolytic enzymes — bromelain and papain — alongside quercetin. This pairing is not a trend or a marketing choice. It follows the formulation rationale that doctors who led the original 2001 quercetin IC pilot study, described in the 2003 review: proteolytic enzymes support the absorption of co-administered actives like quercetin [19].

Designed for sensitive systems

People living with IC/BPS often describe heightened sensitivity to everything they consume — foods, beverages, medications, supplements. A formula designed for IC must account for this. CYSTUROL's use of papain and bromelain contributes to the formula's gastrointestinal profile: proteolytic enzymes have a long history of use in supporting digestive tolerance, and the formula's excipients (vegan hypromellose capsule, microcrystalline cellulose, magnesium stearate, silicon dioxide) are selected to keep the finished capsule non-acidic and easy on sensitive systems.

Cranberry is included as whole-fruit powder in capsule form specifically to avoid the acid load associated with cranberry juice products. The calming herbs — passion flower, valerian, wood betony — contribute to the formula's role in the broader picture of living with a chronic bladder condition, including the sleep and stress dimensions that bladder symptoms disrupt.

Pharmaceutical-grade manufacturing

CYSTUROL is manufactured in a GMP-certified facility to pharmaceutical-grade quality standards. Each batch is assayed for ingredient identity, potency, and contaminants before it leaves the facility. This is not the standard across the dietary supplement industry — it's the standard Sunn Biolabs sets because our customers include people who've been chasing symptom relief for years (often a decade or more, from first symptoms to diagnosis) and deserve formulas made to the same rigor as prescription manufacturing.

Refined by a Medical Advisory Board

CYSTUROL's formulation is reviewed and refined by Sunn Biolabs' Medical Advisory Board, a group of practicing urologists with expertise in interstitial cystitis, chronic pelvic pain, and urologic health. Our MAB reviews ingredient selection, dosing, manufacturing protocols, and clinical evidence on an ongoing basis.

Part of a multi-modal approach

The 2022 American Urological Association IC/BPS guideline explicitly reframed IC as a chronic pain syndrome requiring individualized, multi-modal care — behavioral strategies, oral medicines, bladder instillations, procedures, and where appropriate, surgery — rather than a stepwise treatment ladder [9]. CYSTUROL is designed to fit within this multi-modal approach, not to replace professional diagnosis or comprehensive care.

For most people living with IC/BPS, supportive dietary strategy is part of daily life — avoiding the acids, caffeine, and trigger foods that provoke flares. CYSTUROL is formulated to be compatible with that sensitive-bladder dietary approach: whole-fruit cranberry powder rather than juice, non-acidic excipients, calming herbs that support the sleep and stress-axis dimensions of living with a chronic condition.

Anyone experiencing persistent pelvic pain, urinary urgency, frequency, nocturia, or other symptoms consistent with IC/BPS should work with a qualified urologist or urogynecologist to build an individualized care plan. Natural formulas like CYSTUROL are one component of the behavioral / oral-supportive dimension of care — not a substitute for specialist evaluation or FDA-approved therapies.

Full references

All citations are peer-reviewed and PubMed-indexed. Click a PubMed ID (PMID) to read the original paper.

  1. Berry SH, Elliott MN, Suttorp M, et al. Prevalence of symptoms of bladder pain syndrome/interstitial cystitis among adult females in the United States. J Urol. 2011;186(2):540–4. PMID: 21683389
  2. Suskind AM, Berry SH, Ewing BA, et al. The prevalence and overlap of interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome in men: results of the RAND Interstitial Cystitis Epidemiology male study. J Urol. 2013;189(1):141–5. PMID: 23164386
  3. Wyndaele JJJ, Riedl C, Taneja R, et al. GAG replenishment therapy for bladder pain syndrome/interstitial cystitis. Neurourol Urodyn. 2019;38(2):535–544. PMID: 30592544
  4. Sant GR, Kempuraj D, Marchand JE, Theoharides TC. The mast cell in interstitial cystitis: role in pathophysiology and pathogenesis. Urology. 2007;69(4 Suppl):34–40. PMID: 17462477
  5. Theoharides TC, Kempuraj D, Sant GR. Mast cell involvement in interstitial cystitis: a review of human and experimental evidence. Urology. 2001;57(6 Suppl 1):47–55. PMID: 11378050
  6. Clemens JQ, Mullins C, Ackerman AL, et al. Urologic chronic pelvic pain syndrome: insights from the MAPP Research Network. Nat Rev Urol. 2019;16(3):187–200. PMID: 30560936
  7. O'Leary MP, Sant GR, Fowler FJ Jr, Whitmore KE, Spolarich-Kroll J. The interstitial cystitis symptom index and problem index. Urology. 1997;49(5A Suppl):58–63. PMID: 9146003
  8. Lubeck DP, Whitmore K, Sant GR, Alvarez-Horine S, Lai C. Psychometric validation of the O'Leary-Sant Interstitial Cystitis Symptom Index in a clinical trial of pentosan polysulfate sodium. Urology. 2001;57(6 Suppl 1):62–6. PMID: 11378052
  9. Clemens JQ, Erickson DR, Varela NP, Lai HH. Diagnosis and treatment of interstitial cystitis/bladder pain syndrome: AUA guideline. J Urol. 2022;208(1):34–42. PMID: 35536143
  10. Katske F, Shoskes DA, Sender M, Poliakin R, Gagliano K, Rajfer J. Treatment of interstitial cystitis with a quercetin supplement. Tech Urol. 2001;7(1):44–6. PMID: 11272677
  11. Theoharides TC, Sant GR. A pilot open label study of Cystoprotek in interstitial cystitis. Int J Immunopathol Pharmacol. 2005;18(1):183–8. PMID: 15698523
  12. Theoharides TC, Kempuraj D, Vakali S, Sant GR. Treatment of refractory interstitial cystitis/painful bladder syndrome with CystoProtek — an oral multi-agent natural supplement. Can J Urol. 2008;15(6):4410–4. PMID: 19046494
  13. Shoskes DA. Quercetin for chronic prostatitis/chronic pelvic pain syndrome. Urol Clin North Am. 2011;38(3):279–84. PMID: 21798389
  14. Weng Z, Zhang B, Asadi S, et al. Quercetin is more effective than cromolyn in blocking human mast cell cytokine release and inhibits contact dermatitis and photosensitivity in humans. PLoS ONE. 2012;7(3):e33805. PMID: 22470478
  15. Li Y, Yao J, Han C, et al. Quercetin, inflammation and immunity. Nutrients. 2016;8(3):167. PMID: 26999194
  16. Chen H, et al. Identification of key pathways and mRNAs in interstitial cystitis/bladder pain syndrome treatment with quercetin through bioinformatics analysis of mRNA-sequence data. 2024. PMC11042929
  17. Pavan R, Jain S, Shraddha, Kumar A. Properties and therapeutic application of bromelain: a review. Biotechnol Res Int. 2012;2012:976203. PMID: 23304525
  18. Brien S, Lewith G, Walker A, et al. Bromelain as a treatment for osteoarthritis: a review of clinical studies. Evid Based Complement Alternat Med. 2004;1(3):251–7. PMID: 15841258
  19. Shoskes DA, Manickam K. Herbal and complementary medicine in chronic prostatitis. World J Urol. 2003;21(2):109–13. PMID: 12720037
  20. Muss C, Mosgoeller W, Endler T. Papaya preparation (Caricol) in digestive disorders. Neuro Endocrinol Lett. 2013;34(1):38–46. PMID: 23524622
  21. Williams G, Stothart CI, Hahn D, et al. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2023;11(11):CD001321.
  22. Howell AB. Bioactive compounds in cranberries and their role in prevention of urinary tract infections. Mol Nutr Food Res. 2007;51(6):732–7. PMID: 17487930
  23. Movafegh A, Alizadeh R, Hajimohamadi F, Esfehani F, Nejatfar M. Preoperative oral Passiflora incarnata reduces anxiety in ambulatory surgery patients: a double-blind, placebo-controlled study. Anesth Analg. 2008;106(6):1728–32. PMID: 18499602
  24. Janda K, Wojtkowska K, Jakubczyk K, Antoniewicz J, Skonieczna-Żydecka K. Passiflora incarnata in neuropsychiatric disorders — a systematic review. Nutrients. 2020;12(12):3894. PMID: 33352740
  25. Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res. 2011;25(8):1153–9. PMID: 21294203
  26. Miroddi M, Calapai G, Navarra M, Minciullo PL, Gangemi S. Passiflora incarnata L.: ethnopharmacology, clinical application, safety and evaluation of clinical trials. J Ethnopharmacol. 2013;150(3):791–804. PMID: 24140586
  27. Shinjyo N, Waddell G, Green J. Valerian root in treating sleep problems and associated disorders — a systematic review and meta-analysis. J Evid Based Integr Med. 2020;25:2515690X20967323. PMID: 33086877
  28. Bent S, Padula A, Moore D, Patterson M, Mehling W. Valerian for sleep: a systematic review and meta-analysis. Am J Med. 2006;119(12):1005–12. PMID: 17145239
  29. Benke D, Barberis A, Kopp S, et al. GABA-A receptors as in vivo substrate for the anxiolytic action of valerenic acid, a major constituent of valerian root extracts. Neuropharmacology. 2009;56(1):174–81. PMID: 18602406
  30. Khom S, Baburin I, Timin E, et al. Valerenic acid potentiates and inhibits GABA(A) receptors: molecular mechanism and subunit specificity. Neuropharmacology. 2007;53(1):178–87. PMID: 17585957
  31. Miyase T, Yamamoto R, Ueno A. Phenylethanoid glycosides from Stachys officinalis. Phytochemistry. 1996;43(2):475–9. PMID: 8862039
  32. Tomou EM, Barda C, Skaltsa H. Genus Stachys: a review of traditional uses, phytochemistry and bioactivity. Medicines (Basel). 2020;7(10):63. PMID: 33092186

These statements have not been evaluated by the Food and Drug Administration. CYSTUROL is a dietary supplement and is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult your healthcare provider before starting any new dietary supplement, particularly if you are pregnant or nursing, have a medical condition, or are taking prescription medications. The peer-reviewed research cited on this page summarizes studies of individual ingredients and of related formulations; it does not constitute clinical evidence specific to CYSTUROL as a finished product.