Ketamine Induced Cystitis

Ketamine Induced Cystitis

In this month’s blog post, I want to talk about Ketamine Induced Cystitis, also known as Ketamine Bladder Syndrome or, more informally, as simply ketamine bladder.  I have occasionally been asked if aloe vera can help with bladder pain related to ketamine use and I thought it might be interesting to write about the topic here. 

Ketamine is an anaesthetic with dissociative and sedative properties.  In the UK, it is used in both human and veterinary medicine, but is has also been taken as a recreational drug since the 1970s.  In recent years, such recreational misuse has increased drastically.  In 2007, twelve months after ketamine was made an illegal Class C drug, only 0.8% of 16-24 year olds reported having used it in that year1.  By 2011, this figure had risen to 2.1%2 and ketamine was reclassified as a Class B drug in 2014.  As of March 2023, 3.8% of 16-24 year olds reported having used it in the last twelve months3.  Worryingly, an anonymous survey of 13,000 secondary schoolchildren revealed that 0.9% of respondents had tried it4. 


Part of the reason for the rise in ketamine misuse is thought to be due to the cost.  Compared to other party drugs, it is relatively cheap; indeed it is often more affordable than cannabis or alcohol.  This means that it is well within the reach of those on pocket money or Saturday job budgets.  Its affordability and ubiquitousness mean ketamine can be purchased easily – apparently even at schools or parks.  This sets it apart from drugs like cocaine or heroin, which require significant funds and more specialised connections to procure. 


When used recreationally, ketamine is usually snorted, though less commonly it might be taken orally or injected.  It begins to work from almost immediately to within 30 minutes, depending on how it is taken, with ‘the buzz’ generally lasting for 30-60 minutes.  An additional 1-2 hours of lingering effects may be felt thereafter.  Its metabolites can be detected in blood for up to 24 hours after use, in saliva for up to 48 hours, in urine for up to a month, and in hair for up to three months5.  As this blog is to focus on ketamine induced cystitis, the timelines for detection of metabolites in urine will be of particular interest. 


The effects of ketamine are dose dependent, but include feelings of relaxation and detachment, euphoria, and altered perceptions of space or time.  At lower doses the effects may be similar to alcohol, prompting similar physical reactions of clumsiness, heaviness, and floppiness.  At higher doses, ketamine might cause hallucinations and feelings of dissociation from one’s own body.  A state colloquially known as a K-hole occurs when users become so dissociated and physically impaired that they are unable to move or interact with their surroundings.  Given ketamine’s therapeutic use as an anaesthetic, there are also sedating and pain-relieving effects6. 


Like most recreational drugs, ketamine has dangerous side effects.  Aside from the risks inherent in being physically impaired and mentally detached from reality, users might also experience elevated heart rate, high blood pressure, nausea and vomiting.  The latter of these can be fatal in cases where users have been rendered immobile in a supine position; therefore people in the midst of a K-hole should be placed into the recovery position to prevent them from choking.  One particularly debilitating side effect of ketamine that most users don’t know about until it happens to them is ketamine bladder.  This is the effect with which we will concern ourselves for the remainder of this post. 


Symptoms of ketamine bladder are similar to those of bladder infections or interstitial cystitis and include:

  • Increased urinary frequency, i.e. needing to urinate more often.  Some sufferers need to pass urine every half hour7.
  • Increased urinary urgency, i.e. needing to urinate as soon as the urge strikes and not being able to hold it. 
  • Nocturia, i.e. needing to get up in the night to pass urine. 
  • Pain and burning when passing urine.
  • Urinary retention, i.e. inability to fully empty the bladder.
  • Blood in the urine.
  • Bladder shrinkage and decreased bladder capacity, i.e. not being able to store very much urine. 
  • Urinary incontinence, i.e. bladder leaks or wetting yourself8. 
  • Intense pain and pressure in the lower abdomen.  Feelings of burning and squeezing in the bladder area.  Inflammation in the bladder itself.  The pain may be continuous9.
  • Increased risk of urinary infections.
  • Scarring and thickening of the bladder wall10.
  • Ureteral stenosis – scarring and narrowing of the tubes that carry urine from the kidneys to the bladder.  This can cause back pain, flank pain, fever, nausea, chronic bladder infections, and kidney damage.
  • Kidney pain, kidney damage and even eventual kidney failure11.


Ketamine bladder commonly develops over two years of regular ketamine use.  The risk increases with frequency of use, duration of use, and quantity consumed.  Simply put, the more often you use ketamine, the longer you use it for, or the more of it you take in one go, the more likely you are to develop bladder pain12.  This does not mean that using ketamine is ever safe though; even occasional use can cause bladder problems for some13.  Although it is commonly reported that 20-30% of ketamine users will experience urinary tract symptoms, studies from Spain and Hong Kong indicate that the real number lies between 46% and 90%14. 


One early warning sign of bladder damage might be the strong abdominal cramps known as K-cramps15.  When initially experienced, these normally subside within 24 hours of the last dose of ketamine being taken.  However, if ketamine use continues, the cramps are likely to recur and worsen.  The cramps, along with the urinary symptoms listed above, are extremely painful.  One ex-user who has been left unable to work because of the pain he is in describes his experience as, “Like urinating shards of glass.  I was in agony.  An addiction to ketamine has ruined my life.”16


The pain of ketamine bladder often leads to a particularly cruel vicious circle.  Because ketamine is an anaesthetic, users find themselves taking more of it to dull the pain it causes17.  As their tolerance for it increases and when it wears off, they are left in even more pain, leading them to take even more ketamine.  This can eventually cause permanent bladder damage18.  In severe cases of Ketamine Induced Cystitis, bladder damage or shrinkage becomes advanced enough that bladder removal is required19. 


The exact mechanism by which ketamine causes bladder injury is not known.  One theory is that ketamine and its metabolites, which are largely excreted in the urine, directly damage the bladder lining when they come into contact with it.  This is supported by a rare case study concerning a patient who had a urachal cyst at the top of her bladder which did not come into contact with her urine.  Whereas the rest of her bladder lining was damaged, the lining of the urachal cyst remained healthy20.  Another study found that ketamine’s main metabolite, norketamine, is significantly more damaging to bladder cells than ketamine itself21.


The ulceration of the bladder lining seen in ketamine users is similar to the lesions known as Hunner lesions found in some interstitial cystitis sufferers.  It bears noting that such lesions in the latter group are not found in all cases, or even a majority of cases, and an interstitial cystitis diagnosis can still be reached in their absence.  Both ketamine induced bladder ulceration and Hunner lesions represent physical damage to the protective glycosaminoglycan (GAG) layer of the bladder.  By the time ulcers are visible, there is complete erosion of sections of this layer, leading to intense pain.  In the early stages before ulceration occurs, GAG layer damage may not be visible, but may still be sufficient to cause symptoms via ‘leaky bladder’ whereby urinary irritants pass into the bladder wall causing inflammation, pain and nerve damage22. 


Another theory is that ketamine causes bladder pain via inflammatory responses or hypersensitivity reactions.  Ketamine users frequently show mast cell and eosinophil infiltration, increased COX-2 expression23, upregulation of iNOS and eNOS (two forms of nitric oxide synthase), and elevated serum IgE.  Interestingly, one study revealed that interstitial cystitis sufferers also have higher serum IgE than those with acute bacterial cystitis or control participants.  However, their IgE levels were lower than for the ketamine group24. 


Other theories involve the idea that ketamine stimulates the release of chemicals that lead to changes in the bladder wall, cause inflammation, or cause nerve damage.  The pain of Ketamine Induced Cystitis is thought to be associated with an abnormal increase of nerve cells in the layer of the bladder wall that lies beneath the mucosal layer, as well as prominent nerve bundles superficially.  Interestingly, this does not occur in other painful bladder conditions. 


There are three stages of Ketamine Bladder Syndrome: 

  • In stage 1 there is inflammation, which may cause various of the urinary tract symptoms outlined above.  However, there is no fibrosis, shrinking, or thickening of the bladder, and the ureters and kidneys are normal.  At this stage, symptoms are reversible. 
  • In stage 2, there are structural changes to the bladder, including scarring, thickening, and reduced capacity.  Urinary tract symptoms and pain are likely to be more severe.  The ureters may or may not be affected; kidney function is normal.  At this stage, the bladder can be salvaged and symptoms can be improved.  Resolution of symptoms may take a long time and be incomplete. 
  • In stage 3, there are severe structural changes to the bladder.  Urinary tract symptoms and pain are likely to be very debilitating.  The ureters will be inflamed; the kidneys may be swollen and there may be partial or total kidney failure.  At this stage, surgical intervention will almost certainly be required and cystectomy (removal of the bladder) may be necessary25.     

Early and occasional lower urinary tract symptoms of ketamine use are almost always reversible.  One study found that 51% of ketamine users experienced improvement in urinary symptoms once they stopped using the drug26.  However, as another study starkly warns:  “Timely recognition may be the difference between mild troublesome LUTSs and radical reconstructive surgery.” 27 


If you are a ketamine user and have not yet developed any bladder symptoms, the safest thing to do is to stop using the drug.  Many people find this relatively easy to do, as ketamine does not produce clinically significant withdrawal syndrome, although there can be some mental health symptoms28.  If you feel unable to stop using ketamine, you should reach out to a trusted adult, a healthcare provider, or a drug recovery organisation immediately.  Continuing to use the drug may cause irreparable damage to your bladder.  Until you are able to abstain from ketamine completely, you may wish to implement some of the strategies outlined below even if you are not experiencing any symptoms of ketamine bladder yet. 


If you are a ketamine user who has started to develop bladder symptoms, you should stop using the drug immediately.  This alone might be enough to reverse early inflammation.  If you are unable to stop using, you should take some or all of the measures outlined in the previous paragraph to get assistance.  Continuing to use the drug will cause further inflammation to your bladder and might cause irreparable damage.  You should also continue reading to discover things that might help to alleviate your bladder pain symptoms in the meantime. 


If you are unable to immediately stop using ketamine, or if you have recently stopped using and are still experiencing intrusive or painful bladder symptoms, here are some things to consider. 


The metabolites of ketamine are traceable in urine for up to a month – perhaps even longer for heavy regular users.  Even occasional or mild Stage 1 symptoms with no structural damage to the bladder might therefore take more than a month to resolve, because during this time, substances that irritate the bladder are still detectable in urine. 


Because ketamine and its metabolites damage the mucosal glycosaminoglycan (GAG) layer of the bladder, taking substances that preserve and restore this protective layer might help to alleviate lower urinary tract symptoms (LUTS).  Herbs and supplements high in mucopolysaccharides should be considered.  Some options are:

  • High potency freeze dried aloe vera capsules, such as Tiny Pioneer Aloe 720 Capsules.  Aloe vera contains a mucopolysaccharide called acemannan, which is known to have anti-inflammatory and wound healing properties.  Aloe vera is listed as a complementary and alternative therapy used by interstitial cystitis patients in a 2002 articles by Kristene E Whitmore29 and I have received feedback from a customer who said that he found our own aloe vera capsules helpful for ketamine bladder pain.  Whether you hope to protect against the onset of ketamine related bladder pain or repair existing damage to the GAG layer, it is my personal opinion that aloe vera capsules could be useful.  Tiny Pioneer Aloe 720 Capsules are high in acemannan, have had the aloin (a harmful laxative component of aloe vera) removed, and contain no fillers or flow agents.  You can read more about acemannan in this blog post and more about aloin in this one.  You can also read about how to choose a good aloe vera product here. 
  • Marshmallow root capsules and/or marshmallow root tea.  Like aloe, marshmallow root contains mucopolysaccharides which may coat and protect the bladder wall.  It also inhibits bacterial growth in the urinary tract, which is relevant because ketamine induced bladder damage leaves patients more susceptible to bacterial cystitis.  Additionally it soothes urinary and kidney inflammation and helps to stop haematuria (blood in the urine)30. 
  • Glucosamine sulphate, chondroitin sulphate and methylsulfonylmethane (MSM).  These ingredients are commonly found combined in one supplement, although you can buy them separately, or with MSM omitted.  Glucosamine and chondroitin are again thought to coat and replenish the bladder lining owing to their amino monosaccharide and mucopolysaccharide structures respectively.  MSM is anti-inflammatory, diminishes iNOS and COX-2 expression, and regulates mast cell activity31.  Chondroitin is commonly administered directly to the bladder via instillations, but this is invasive and accessible only via referral to a specialist.  An oral combination of glucosamine and chondroitin has been found effective in improving interstitial cystitis symptoms32 and it is reasonable to think that this might extend to ketamine bladder.
  • Hyaluronic acid is another mucopolysaccharide that has been shown to improve symptoms of bladder pain when administered via the intravesical route33.  Anecdotally, some interstitial cystitis sufferers have found relief using over the counter oral hyaluronic acid supplements, so these may similarly have a place in prophylaxis against or management of ketamine bladder symptoms. 


Interstitial cystitis sufferers often find temporary relief from symptoms by either drinking bicarbonate of soda dissolved in water or taking calcium glycerophosphate capsules34.  The bicarbonate of soda method dilutes stomach acid and should not be used long term or with food.  It might, however, alleviate the pain of acute ketamine bladder, i.e. temporary flares of bladder pain in situations where the condition has not developed to Stage 2 or 3.  Similarly, calcium glycerophosphate capsules, available from Tiny Pioneer as Calci-G Capsules or Calci-G MAX Capsules, might provide symptomatic relief in mild or Stage 1 cases of Ketamine Bladder Syndrome.  Calcium glycerophophate should not be used in later stages of the condition, as calcium should not be taken by patients with kidney impairment or where kidney stones are a risk.  Unlike bicarbonate of soda, calcium glycerophosphate can be taken with food.    


Interstitial cystitis patients commonly find that ascorbic acid (a form of vitamin C) and vitamin B6 provoke flare ups of symptoms.  I would imagine that these could be similarly aggravating to the inflamed bladders of ketamine users.  If you use ketamine or have residual ketamine bladder symptoms, you might like to check your daily vitamins, supplements, or drinks for ascorbic acid and vitamin B6 (which might be labelled as pyridoxine).  If you suspect that they are making your symptoms worse, you can consider non-acidic, buffered forms of vitamin C, such as magnesium ascorbate.  These are suitable for people with interstitial cystitis and might similarly be gentler for ketamine bladders, although it bears noting that I don’t know for sure!  Likewise, you can choose supplements without vitamin B6, or, if you require supplemental B6, try versions with bioavailable pyridoxal-5’-phosphate (P5P) instead. 


The hypersensitivity reactions described earlier in the post might be alleviated by supplementing with quercetin, which is known to downregulate iNOS and COX-2 expression, stabilise mast cells, and modulate inflammation35.  Again, interstitial cystitis patients often find quercetin helpful in managing symptoms and it stands to reason that ketamine bladder might similarly respond. 


Another agent that inhibits mast cell response and histamine release, as well as reducing COX-2 enzyme production, is palmitoylethanolamide (PEA).  This ingredient has been studied extensively in a range of chronic pain conditions, including neuropathic pain disorders36.  I personally feel it would be an excellent adjunct therapy for patients with Stage 1 Ketamine Induced Cystitis, from both a hypersensitivity reaction and nerve pain angle.  I would not recommend it in cases where the kidneys have become compromised, except under professional direction.  PEA is a popular complementary therapy for interstitial cystitis and I see no reason why this should not be the same for ketamine induced bladder inflammation.  Here at Tiny Pioneer we offer both Simply PEA Capsules and Simply PEA powder. 


Pharmaceutically speaking, those treatments which are commonly used in interstitial cystitis might also be helpful in Ketamine Induced Cystitis.  Aside from the oral analgesics and anti-inflammatories normally prescribed, or the intravesical concoctions administered, pentosan polysulfate sodium (brand name Elmiron) may be considered.  This is the only FDA approved oral medication for the treatment of interstitial cystitis and it has also been effective in Ketamine Induced Cystitis37.


I was interested to see that anti-IgE therapy in the form of omalizumab has been successful in treating interstitial cystitis38 and that it might be prescribed off-label for the same.  Given the elevated IgE status of ketamine bladder patients, it seems likely that their symptoms would be even more responsive to omalizumab, assuming they could tolerate the side effects which sometimes necessitate discontinuation of treatment39.


With regards to addressing bladder pain symptoms, I always advocate for beginning with the least invasive methods and progressing to more invasive interventions (distensions and instillations, for example) if absolutely necessary.  This is a philosophy shared in Figure 1 of the paper entitled Current Approaches for the Treatment of Ketamine-Induced Cystitis40.  I would place the over-the-counter supplements discussed above in the second phase of the diagram, i.e. with oral anti-inflammatory drugs.  


If you are reading this post as a healthcare provider, I hope you will appreciate the references included and will find them useful in directing you to more detailed information about Ketamine-Induced Cystitis.  If you are reading as a ketamine user and have found the material hard-going, please see this more accessible, patient-focused version that might be easier for teens and young adults to follow. 


If you are suffering from ketamine bladder and are feeling disheartened by the information in this post, please rest assured that most people are able to successfully reverse their symptoms.  It is important to get the help you need to stop using ketamine, but the likelihood is that once you do this, your bladder will eventually return to normal.  The supplements I discussed might speed up the process or make it more comfortable in the meantime.  If your ketamine damage is more serious, there is still hope.  Treatments will be more invasive and symptom relief might take longer to happen, but it is often still possible.  Bladder removal is only reserved for severe, end-stage cases of Ketamine-Induced Cystitis and at that point, the prospect of being free from pain is likely to outweigh the grief of living without a bladder.  Anecdotally, many interstitial cystitis patients are relieved to finally have their bladder out and they go on to have happy and pain-free lives thereafter. 


Wishing you the best of health,


Tiny x


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  1. https://www.sciencedirect.com/science/article/abs/pii/S0376871608000550
  2. https://www.drugwise.org.uk/wp-content/uploads/KO.pdf
  3. https://www.ons.gov.uk/peoplepopulationandcommunity/crimeandjustice/articles/drugmisuseinenglandandwales/yearendingmarch2023#overall-trends-in-drug-misuse
  4. https://www.bbc.co.uk/news/articles/c5y0g2gnjrqo
  5. https://www.priorygroup.com/blog/how-long-does-ketamine-stay-in-your-system
  6. https://drugabuse.com/drugs/hallucinogens/ketamine/effects-use/
  7. https://www.bbc.co.uk/news/uk-england-bristol-68826392
  8. https://www.addictioncenter.com/drugs/hallucinogens/ketamine/ketamine-bladder/
  9. https://leaflets.ekhuft.nhs.uk/ketamine-addiction-and-ketamine-bladder-and-induced-cystitis/html/
  10. https://fpm.ac.uk/documents/case-report-41-ketamine-bladder-pain-dr-matthew-cole-and-dr-sunil-dasari/discussion
  11. Anderson DJ, Zhou J, Cao D, McDonald M, Guenther M, Hasoon J, Viswanath O, Kaye AD, Urits I. Ketamine-Induced Cystitis: A Comprehensive Review of the Urologic Effects of This Psychoactive Drug. Health Psychol Res. 2022 Sep 15;10(3):38247. doi: 10.52965/001c.38247. PMID: 36118982; PMCID: PMC9476224.
  12. https://www.addictioncenter.com/drugs/hallucinogens/ketamine/ketamine-bladder/
  13. https://leaflets.ekhuft.nhs.uk/ketamine-addiction-and-ketamine-bladder-and-induced-cystitis/html/ 
  14. Srirangam S, Mercer J. Ketamine bladder syndrome: an important differential diagnosis when assessing a patient with persistent lower urinary tract symptoms. BMJ Case Rep. 2012 Sep 30;2012:bcr2012006447. doi: 10.1136/bcr-2012-006447. PMID: 23035160; PMCID: PMC4544340.
  15. https://www.substancemisuseresources.co.uk/harm-reduction-information/ketamine-and-your-bladder-what-you-need-to-know
  16. https://www.bbc.co.uk/news/articles/czr6emm2xm6o
  17. https://www.midyorks.nhs.uk/news/trust-doctor-warns-about-the-dangers-of-ketamine-misuse-4472/
  18. https://recovered.org/hallucinogens/ketamine/k-cramps
  19. https://leaflets.ekhuft.nhs.uk/ketamine-addiction-and-ketamine-bladder-and-induced-cystitis/html/
  20. Anderson DJ, Zhou J, Cao D, McDonald M, Guenther M, Hasoon J, Viswanath O, Kaye AD, Urits I. Ketamine-Induced Cystitis: A Comprehensive Review of the Urologic Effects of This Psychoactive Drug. Health Psychol Res. 2022 Sep 15;10(3):38247. doi: 10.52965/001c.38247. PMID: 36118982; PMCID: PMC9476224.
  21. Lin JW, Lin YC, Liu JM, Liu SH, Fang KM, Hsu RJ, Huang CF, Chang KY, Lee KI, Chang KC, Su CC, Chen YW. Norketamine, the Main Metabolite of Ketamine, Induces Mitochondria-Dependent and ER Stress-Triggered Apoptotic Death in Urothelial Cells via a Ca2+-Regulated ERK1/2-Activating Pathway. Int J Mol Sci. 2022 Apr 23;23(9):4666. doi: 10.3390/ijms23094666. PMID: 35563057; PMCID: PMC9102902.
  22. https://www.leedsth.nhs.uk/patients/resources/painful-bladder-syndrome-interstitial-cystitis-2/[1]
  23. Chang M, Young A, Juruena M. Ketamine Cystitis Following Ketamine Therapy for Treatment Resistant Depression – Case Report. BJPsych Open. 2025 Jun 20;11(Suppl 1):S295. doi: 10.1192/bjo.2025.10711. PMCID: PMC12260818.
  24. https://www.auajournals.org/doi/10.1016/j.juro.2014.05.084
  25. https://fpm.ac.uk/documents/case-report-41-ketamine-bladder-pain-dr-matthew-cole-and-dr-sunil-dasari/discussion
  26. Winstock, A.R., Mitcheson, L., Gillatt, D.A. and Cottrell, A.M. (2012), The prevalence and natural history of urinary symptoms among recreational ketamine users. BJU International, 110: 1762-1766. https://doi.org/10.1111/j.1464-410X.2012.11028.x
  27. Srirangam S, Mercer J. Ketamine bladder syndrome: an important differential diagnosis when assessing a patient with persistent lower urinary tract symptoms. BMJ Case Rep. 2012 Sep 30;2012:bcr2012006447. doi: 10.1136/bcr-2012-006447. PMID: 23035160; PMCID: PMC4544340.
  28. https://drugabuse.com/drugs/hallucinogens/ketamine/effects-use/
  29. https://pmc.ncbi.nlm.nih.gov/articles/PMC1476005/
  30. https://pmc.ncbi.nlm.nih.gov/articles/PMC10008376/
  31. https://pmc.ncbi.nlm.nih.gov/articles/PMC5372953/#B21-nutrients-09-00290
  32. https://pubmed.ncbi.nlm.nih.gov/19046494/
  33. https://www.sciencedirect.com/science/article/pii/S1028455919300646
  34. https://pmc.ncbi.nlm.nih.gov/articles/PMC1476005/
  35. https://pmc.ncbi.nlm.nih.gov/articles/PMC11985094/
  36. https://www.tinypioneer.co.uk/blog/pea-palmitoylethanolamide-interstitial-cystitis-pain
  37. https://fpm.ac.uk/documents/case-report-41-ketamine-bladder-pain-dr-matthew-cole-and-dr-sunil-dasari/management
  38. https://pubmed.ncbi.nlm.nih.gov/16771742/
  39. https://www.urogynaecologia.org/uij/article/view/uij.2012.e8
  40. https://onlinelibrary.wiley.com/doi/10.1002/nau.25148