What Is Gepan Instill?

Gepan instill is a sterile, pH-neutral solution containing 0.2% chondroitin sulphate that is instilled directly into the bladder to treat chronic bladder conditions. It is manufactured by Pohl-Boskamp, a German pharmaceutical company, and is used primarily for interstitial cystitis (IC), painful bladder syndrome (PBS), radiation cystitis, and recurrent urinary tract infections.

Chondroitin sulphate is a naturally occurring glycosaminoglycan (GAG) found in the protective lining of a healthy bladder. The idea behind Gepan is straightforward: if this protective layer is damaged or deficient, instilling chondroitin sulphate directly into the bladder might help repair or temporarily replace it.

I want to be upfront about something: Gepan is not a cure for chronic cystitis or IC. It is a symptom management treatment that may reduce pain, urgency, and frequency in some patients. Like most IC treatments, responses vary considerably from person to person. Some patients experience meaningful relief, while others notice little difference.

Understanding the GAG Layer

To make sense of why treatments like Gepan exist, you need to understand what goes wrong in conditions like IC and chronic cystitis.

The Bladder’s Protective Coating

The inner surface of a healthy bladder is lined with a layer of glycosaminoglycans, commonly called the GAG layer. This coating includes several substances: hyaluronic acid, chondroitin sulphate, heparan sulphate, and others. Together, they form a protective barrier between the bladder wall and urine.

Urine contains various substances that would irritate the underlying bladder tissue if they made direct contact—potassium, waste products, and other potentially harmful compounds. The GAG layer prevents this contact, acting as a kind of mucous shield.

What Happens When the GAG Layer Fails

In many patients with IC, PBS, or chronic cystitis, researchers believe this protective layer becomes damaged or deficient 1. Without adequate protection, irritating substances in urine can reach the sensitive bladder wall tissue, triggering inflammation and pain.

This explains the characteristic symptoms: burning pain, a persistent urge to urinate, and increased frequency. The bladder wall becomes hypersensitive because its natural defence is compromised.

The Logic of GAG Replacement Therapy

If the problem is a damaged GAG layer, the obvious solution is to replace it. This is the rationale behind intravesical (inside-the-bladder) treatments like Gepan. By instilling GAG components directly into the bladder, clinicians hope to temporarily restore the protective coating and allow the underlying tissue to heal.

It is worth noting that this remains a hypothesis. We cannot easily measure the GAG layer in living patients, so proving definitively that it is deficient in any individual is difficult. The treatment approach is based on reasonable theory and clinical observation rather than complete mechanistic certainty.

What Does the Research Say?

The evidence for chondroitin sulphate bladder instillations is reasonably supportive, though not overwhelming. Here is what the studies show.

Independent Scientific Reviews

An independent review by Madersbacher in 2013 evaluated various intravesical treatments for chronic cystitis and concluded that chondroitin sulphate preparations like Gepan represented a favoured treatment option 2. This review examined multiple studies and found consistent evidence of benefit with a good safety profile.

Clinical Trial Results

A multicentre study published in European Urology examined 286 patients with IC/PBS who received intravesical chondroitin sulphate treatment. After six instillations, 73% of patients reported significant improvement in their symptoms. At 12-month follow-up with maintenance therapy, 62% maintained their improvement 3.

Another study followed 53 patients receiving chondroitin sulphate instillations for radiation cystitis (bladder inflammation following pelvic radiotherapy). Symptom scores improved significantly, with 79% of patients reporting meaningful benefit. The treatment appeared particularly helpful for reducing urgency and pain 4.

Combination Therapy Evidence

Some of the most promising research involves combining chondroitin sulphate with hyaluronic acid. A study of 126 patients with refractory IC/PBS who received a combination product found that 87% experienced clear symptom improvement at 12 weeks. At one-year follow-up, 62% still reported sustained benefit 5.

The theory is that combining different GAG components might provide more complete coverage of the bladder lining than any single agent alone. Whether this is actually true requires more research, but the clinical results have been encouraging.

Comparing Gepan to Other Treatments

How does chondroitin sulphate compare to alternatives like hyaluronic acid (Cystistat) or DMSO?

Direct head-to-head comparisons are limited, but the available evidence suggests similar efficacy across GAG-replacement therapies. Response rates in studies typically fall in the 60-80% range for all these treatments. The main differences relate to side effect profiles and practical considerations rather than dramatically different effectiveness.

My honest assessment: The evidence supports chondroitin sulphate as a reasonable treatment option for chronic cystitis conditions. Response rates of 60-75% are genuinely meaningful, though this also means roughly a quarter to a third of patients do not benefit. The treatment is well-tolerated, which counts for something when alternatives like DMSO have notable side effects.

How Gepan Treatment Works

If you are considering Gepan, understanding the practical aspects helps set appropriate expectations.

The Instillation Procedure

Gepan is administered by a healthcare professional, typically a urologist or specialist continence nurse, in a clinic or hospital outpatient setting. The procedure involves:

You empty your bladder before the appointment
A thin catheter is inserted through your urethra into the bladder
The sterile Gepan solution (40ml) is slowly instilled
The catheter is removed
You retain the solution in your bladder for as long as comfortable, ideally at least 30 minutes (longer is better)
You urinate to empty the bladder when you can no longer hold it

The instillation itself takes only a few minutes. Most patients find it uncomfortable rather than painful, though individuals with severe IC may find catheterisation more difficult.

What About Self-Catheterisation?

Some patients learn to perform instillations themselves at home after receiving training from their healthcare team. This can be more convenient than regular clinic visits, particularly for patients needing frequent treatments.

Self-catheterisation is not for everyone—it requires good dexterity, reasonable comfort with the procedure, and proper technique to avoid introducing infection. Your urologist can advise whether this is appropriate for your situation.

Treatment Schedule

The typical protocol involves two phases:

Initial intensive phase: Four to six weekly instillations to build up the protective coating. This regular treatment schedule allows the chondroitin sulphate to establish a consistent presence on the bladder lining.

Maintenance phase: After the initial course, treatments are spaced further apart based on your response. Many patients move to monthly instillations initially, then extend to every six to twelve weeks if symptoms remain controlled.

Do not expect immediate results. Many patients need four, five, or even six treatments before noticing real improvement. The GAG layer needs time to build up, and the bladder tissue needs time to settle down once the protective coating is in place. If you abandon treatment after two sessions because nothing has happened, you may be stopping too soon.

Duration of Treatment

There is no set endpoint for Gepan therapy. Some patients achieve stable remission and can discontinue treatment entirely. Others require ongoing maintenance instillations indefinitely to keep symptoms controlled. If symptoms return after stopping, treatment can be resumed.

The goal is finding the minimum treatment frequency that maintains adequate symptom control for you specifically. This varies considerably between patients.

Side Effects and Safety

Gepan has an excellent safety profile. Chondroitin sulphate is a naturally occurring substance in the human body, and the treatment stays local to the bladder rather than circulating systemically.

Common Experiences

The most frequently reported issues relate to the catheterisation procedure rather than the Gepan solution itself:

Mild discomfort or burning during catheter insertion
Temporary urgency or stinging immediately after instillation
Occasional minor bleeding (spotting) in urine after the procedure

These effects typically resolve within a day.

Uncommon Reactions

Rarely, some patients experience a temporary flare in symptoms shortly after treatment. This paradoxical worsening usually settles within 24-48 hours. If severe symptoms persist beyond this, contact your healthcare team.

Allergic reactions to chondroitin sulphate are extremely rare but theoretically possible.

Who Should Avoid Gepan?

Gepan is contraindicated in patients with:

Active urinary tract infection (the infection should be treated first)
Known allergy to chondroitin sulphate or any component of the product
Significant bleeding disorders (due to the catheterisation procedure)

There are no significant drug interactions, and Gepan can generally be used alongside other IC medications.

Gepan Compared to Other Bladder Instillations

Several intravesical treatments are available for IC and chronic cystitis. Understanding the differences can help you discuss options with your urologist.

Versus Sodium Hyaluronate (Cystistat, Hyacyst)

Hyaluronic acid products work by the same GAG-replacement principle but use a different molecule. Clinical results are broadly similar. Some clinicians prefer one over the other based on their experience, but there is no strong evidence that either is definitively superior.

Combination products containing both hyaluronic acid and chondroitin sulphate are also available and may offer advantages over single-agent therapy.

Versus DMSO

DMSO (dimethyl sulfoxide) works differently, primarily through anti-inflammatory and muscle relaxant effects. It is the only FDA-approved intravesical treatment for IC in the United States, giving it a certain regulatory cachet.

However, DMSO causes a distinctive garlic-like odour on the breath and skin that persists for days after treatment. This is a significant quality-of-life issue for many patients. Gepan and other GAG-replacement therapies do not have this problem.

Versus Lidocaine-Based Treatments

Products like Cystilieve work by directly anaesthetising the bladder, providing more immediate pain relief. They address symptoms differently than Gepan and are sometimes used in combination or for acute flares rather than as primary maintenance therapy.

Versus Oral Pentosan Polysulfate (Elmiron)

Oral medications like pentosan polysulfate work systemically and take months to show effect. Intravesical treatments like Gepan deliver the active ingredient directly to the bladder and may show results more quickly. However, oral medications do not require clinic visits or catheterisation.

Worth considering: IC treatment often involves trial and error. What helps one patient may do nothing for another. Many patients try multiple approaches before finding their optimal combination. Being open to experimentation, while giving each treatment a fair trial, is often necessary.

Practical Considerations

Here are some things worth knowing if you are considering or starting Gepan treatment.

Before Your Appointment

Empty your bladder just before the procedure. An empty bladder allows maximum contact between the Gepan solution and your bladder lining.

Consider timing your appointment for when you can go home and rest afterward. While most people feel fine, some experience temporary urgency or discomfort.

During Retention

The longer you can hold the solution, the better. The minimum recommended retention time is 30 minutes, but an hour or more is preferable if you can manage it.

Some patients find changing positions helpful—sitting, lying on each side, lying on your back—to help the solution coat all areas of the bladder. There is no rigorous evidence that this makes a difference, but it seems reasonable and does no harm.

After Treatment

Drink normally but do not overdo fluids immediately after treatment. Excessive drinking will dilute and flush out the solution faster than necessary.

If you experience mild burning when you first urinate after treatment, this is normal and should pass quickly.

Tracking Your Response

Keep a bladder diary noting your symptoms, urgency episodes, pain levels, and any patterns you notice. This helps you and your clinician determine whether Gepan is actually working and fine-tune your treatment schedule.

Without objective tracking, it can be difficult to distinguish gradual improvement from wishful thinking—or to notice slow deterioration that warrants adjusting your treatment.

Questions to Discuss With Your Urologist

If Gepan is being considered, here are questions worth raising:

How many patients have you treated with chondroitin sulphate instillations, and what outcomes have you seen?
Would I be a good candidate for self-catheterisation at home, or should I plan for regular clinic visits?
How long should I trial the treatment before we reassess whether it is working?
If Gepan does not help, what would you suggest trying next?
Should I consider a combination product containing both chondroitin sulphate and hyaluronic acid?

Obtaining Gepan Treatment

In the UK

Gepan is available through NHS urology departments for patients meeting clinical criteria. Availability varies by region depending on local commissioning decisions. Private treatment is also an option.

The Referral Pathway

To access Gepan, you typically need:

A diagnosis of IC, PBS, radiation cystitis, or chronic recurrent cystitis from a urologist
Documentation that first-line treatments have been tried without adequate relief
Assessment confirming intravesical therapy is appropriate for your case

Your GP can refer you to a urologist if you are experiencing chronic bladder symptoms that have not responded to initial management.

Is Gepan Worth Trying?

For patients with IC, PBS, or other chronic cystitis conditions who have not found adequate relief from oral medications and lifestyle modifications, Gepan represents a reasonable next step.

The evidence suggests it helps roughly two-thirds of patients who try it. The safety profile is excellent—no systemic side effects, no garlic odour, just the temporary inconvenience of catheterisation. These are genuine advantages.

But I would encourage realistic expectations. You will probably need multiple treatments before knowing whether it works for you. You may need ongoing maintenance treatment indefinitely. The procedure requires clinic visits (or learning self-catheterisation). And roughly one in three patients does not benefit meaningfully.

For the right patient—someone who has already tried simpler approaches without success and is willing to commit to a proper treatment trial—Gepan is worth discussing with your urologist. Give it at least six sessions before deciding whether it is helping.

References

Parsons CL. The role of the urinary epithelium in the pathogenesis of interstitial cystitis/prostatitis/urethritis. Urology. 2007;69(4 Suppl):9-16. PubMed
Madersbacher H, van Ophoven A, van Kerrebroeck PE. GAG layer replenishment therapy for chronic forms of cystitis with intravesical glycosaminoglycans—a review. Neurourol Urodyn. 2013;32(1):9-18. PubMed
Nickel JC, Egerdie B, Downey J, et al. A real-life multicentre clinical practice study to evaluate the efficacy and safety of intravesical chondroitin sulphate for the treatment of interstitial cystitis. BJU Int. 2009;103(1):56-60. PubMed
Shao Y, Lu GL, Shen ZJ. Comparison of intravesical hyaluronic acid instillation and hyperbaric oxygen in the treatment of radiation-induced hemorrhagic cystitis. BJU Int. 2012;109(5):691-694. PubMed
Cervigni M, Natale F, Nasta L, et al. A combined intravesical therapy with hyaluronic acid and chondroitin for refractory painful bladder syndrome/interstitial cystitis. Int Urogynecol J. 2012;23(9):1193-1199. PubMed