How Long Does Ketamine Stay in Your System? Detection Times, Drug Tests, and Health Risks

Ketamine stays in your system for up to 14 days in urine and up to 90 days in hair, though the drug’s effects wear off within 30 to 90 minutes. The gap between how long the effects last and how long the drug is detectable exists because the body converts ketamine into metabolites — breakdown products that linger in tissue and urine long after the high is gone.

Ketamine is a Schedule III controlled substance in the US, used medically as an anesthetic and, in its esketamine form (brand name Spravato), as an FDA-approved treatment for treatment-resistant depression. Recreationally, it is misused for its dissociative and hallucinogenic effects. Understanding how long it remains detectable is clinically important for drug testing, safety, and recognizing signs of problematic use (Rosenbaum et al., 2024).

Key Facts

• Ketamine’s half-life is 2 to 3 hours, but metabolites last much longer: The half-life of ketamine (the time for blood levels to drop by half) is approximately 2 to 3 hours. However, its primary metabolite norketamine has a half-life of roughly 5 hours, and both norketamine and dehydronorketamine are detectable in urine for days after use (Rosenbaum et al., 2024).
• Chronic users test positive in urine for up to 30 days: In people who use ketamine repeatedly, metabolites accumulate and take longer to clear. A case series found prolonged norketamine excretion in urine lasting several weeks after the last dose in chronic users, compared to just a few days in single-dose cases (Moeller et al., 2017).
• Over 25% of regular recreational ketamine users develop bladder damage: Ketamine-induced uropathy (KIU) — serious, sometimes irreversible damage to the bladder and urinary tract — occurs in over 25% of people who use ketamine regularly. This complication is almost absent from popular articles on ketamine, yet it is one of the most clinically relevant risks of recreational ketamine use (Belal et al., 2024).
• Ketamine was involved in a rapid increase in misuse among young adults: UK data show that ketamine use among 16 to 24-year-olds nearly doubled from 1.7% to 3.2% between 2010 and 2020. Recreational ketamine is now classified as a Class B drug in the UK, and its misuse is rising in both the US and Europe (Belal et al., 2024).
• Hair tests detect ketamine for up to 90 days: Hair follicle testing has the longest detection window of all testing methods. Ketamine deposits into the hair shaft as it grows, making hair analysis valuable for establishing patterns of historical use rather than just recent exposure (Staub et al., 2018).

What Is Ketamine and How Is It Used?

Ketamine is a dissociative anesthetic, a drug that produces a trance-like state combining pain relief, sedation, and altered perception by blocking NMDA receptors (proteins in the brain that respond to the neurotransmitter glutamate and play a key role in pain signaling and memory). It was first synthesized in 1962 and received FDA approval for anesthesia in 1970.

Medically, ketamine is used for short procedures that do not require muscle relaxation, as an induction agent before general anesthesia, for pain management in emergency settings, and, in its esketamine form, as a nasal spray for treatment-resistant depression and suicidal ideation. These therapeutic doses are carefully controlled and far lower than recreational doses (Rosenbaum et al., 2024).

Recreationally, ketamine is snorted, swallowed in powder or tablet form, or injected. High doses produce a state called the ‘K-hole’ — a profound dissociation from one’s body and surroundings that users describe as an out-of-body experience. The drug is sometimes used in drug-facilitated crimes because of its sedative effects and the fact that it is odorless and colorless in liquid form.

How Long Do the Effects of Ketamine Last?

The effects of ketamine last between 15 minutes and 90 minutes, depending on the method of use, dose, and individual tolerance. The onset and duration differ by route of administration.

Effects by route of administration (Rosenbaum et al., 2024):

• Intravenous (IV) injection: Onset within 30 seconds. Effects last 15 to 30 minutes. Most rapid delivery method; used medically.
• Intramuscular (IM) injection: Onset in 3 to 5 minutes. Effects last 30 to 60 minutes.
• Snorting (intranasal): Onset in 10 to 15 minutes. Effects last up to 60 minutes, sometimes longer at high doses.
• Swallowing: Onset in 20 to 30 minutes due to slower gut absorption. Effects last 60 to 90 minutes or more.

Common effects include euphoria, pain relief, an altered sense of time and space, hallucinations, and detachment from the body. At high doses, the K-hole experience involves near-complete dissociation. Negative effects include confusion, nausea, increased heart rate, and impaired coordination (Zanos et al., 2018).

Because ketamine impairs judgment and coordination, using it in any setting outside of supervised medical care carries real risk of injury, accident, and overdose, particularly when combined with alcohol, opioids, or other central nervous system depressants.

How Does the Body Process and Eliminate Ketamine?

Ketamine’s liver metabolism produces norketamine and dehydronorketamine — metabolites that remain detectable in urine far longer than the drug itself.

The body processes ketamine primarily through the liver, using a family of enzymes called CYP450 (cytochrome P450) enzymes. These enzymes convert ketamine into norketamine, its primary active metabolite (a breakdown product that still has pharmacological effects). Norketamine is then converted further into dehydronorketamine and hydroxynorketamine metabolites, which are largely inactive.

Between 85% and 95% of a ketamine dose is eliminated via the urine, primarily as metabolites rather than as the unchanged drug. The small remainder is excreted through bile and feces (Zanos et al., 2018).

An important clinical point: Norketamine itself has a longer half-life than ketamine, approximately 5 hours compared to ketamine’s 2 to 3 hours. This means norketamine lingers in the body and contributes both to prolonged effects in some users and to a longer urine detection window than the parent drug alone would suggest (Rosenbaum et al., 2024).

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Factors That Affect How Quickly Ketamine Clears

The factors that affect how quickly ketamine clears are:

• Liver health: Since the liver handles most ketamine metabolism, liver disease or reduced liver function slows clearance.
• Frequency and duration of use: Occasional single-dose users clear ketamine much faster than chronic daily users. With repeated use, metabolites accumulate in fatty tissue and take longer to exit the body.
• Dose taken: Higher doses produce more metabolites that take longer to process and excrete.
• Age and body composition: Older adults and people with higher body fat percentages metabolize drugs more slowly due to changes in liver enzyme activity and drug distribution.
• Route of administration: Intravenous delivery produces higher peak blood levels than snorting or swallowing, which affects the total metabolic burden the liver processes.
• Polydrug use: Combining ketamine with alcohol or other drugs that compete for the same CYP450 liver enzyme slows ketamine metabolism considerably.

How Long Does Ketamine Show Up on Drug Tests?

Ketamine shows up on drug tests for different lengths of time depending on the type of test, the amount used, and how frequently it was taken. The detection windows below represent averages for moderate to occasional use. Chronic or heavy users expect the upper end of these ranges or beyond (Moeller et al., 2017; Rosenbaum et al., 2024).

Ketamine Detection Windows by Test Type

Test type	Detection window	What it detects	Key notes
Urine	Up to 14 days (single use); up to 30 days in chronic, heavy users	Norketamine and dehydronorketamine metabolites	Most common test type. Metabolites persist long after ketamine itself has cleared. Chronic users test positive for weeks (Moeller et al., 2017).
Blood	24 to 72 hours	Ketamine and norketamine in plasma	Short window makes blood testing most useful for acute intoxication, emergency, or post-incident evaluation.
Saliva	Up to 24 hours	Ketamine parent compound	Shortest detection window. Used mainly for roadside testing or suspected very recent use.
Hair	Up to 90 days (3 months)	Ketamine and metabolites deposited in hair shaft	Longest window. Useful for establishing historical use patterns. Particularly valuable in drug-facilitated sexual assault investigations (Staub et al., 2018).

Standard workplace drug panels (the common 5-panel or 10-panel screens) do not typically include ketamine. Detection usually requires a specifically ordered ketamine panel. This is clinically important: a negative standard drug test does not rule out ketamine use.

Attempting to accelerate ketamine clearance by drinking large amounts of water, taking detox kits, or using diuretics does not work reliably. The body clears ketamine through liver metabolism, a process with a fixed biological rate that cannot be meaningfully shortened through hydration or supplements (Rosenbaum et al., 2024).

What Are the Long-Term Health Risks of Regular Ketamine Use?

The long-term health risks of regular ketamine use include bladder and urinary tract damage, cognitive impairment, psychological dependence, and nasal damage from snorting. Of these, ketamine-induced uropathy is the most clinically relevant and the least widely understood.

Ketamine-Induced Uropathy (Bladder Damage)

Ketamine-induced uropathy (KIU) is serious damage to the bladder, ureters, and, in severe cases, the kidneys, caused by chronic recreational ketamine use. It was first described in medical literature in 2007 and is now recognized as a major complication of long-term ketamine misuse.

Because ketamine and its metabolites are excreted through urine, they have direct toxic contact with the bladder lining on every use. Over time, this causes inflammation, scarring, and loss of bladder capacity. Urinary symptoms occur in over 25% of regular recreational ketamine users and are directly correlated with dose and duration of use (Belal et al., 2024).

Symptoms of KIU include urinary urgency and frequency, pelvic pain, blood in the urine (hematuria), and burning during urination. In severe cases, the bladder shrinks to a fraction of its normal capacity, requiring surgical reconstruction or removal. Stopping ketamine use early is the best and sometimes only way to prevent permanent damage (Katsiari et al., 2024).

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Cognitive Effects

Regular ketamine use is associated with impairments in working memory (the ability to hold and use information in the short term), episodic memory, and attention. These deficits have been documented in recreational users and appear to worsen with heavier, longer-term use (Zanos et al., 2018).

Psychological Dependence and Withdrawal

Ketamine does not cause the severe physical withdrawal seen with opioids or alcohol, but it produces substantial psychological dependence. Regular users develop strong cravings, low mood, and anxiety when stopping. Common withdrawal symptoms include:

• Depression and low mood
• Intense drug cravings
• Anxiety, irritability, and agitation
• Insomnia and fatigue
• Difficulty concentrating
• Paranoia or psychotic symptoms in heavy users

Psychological withdrawal symptoms are severe enough to require supervised medical support, particularly in people who were using high doses daily. The severity of withdrawal is generally proportional to the duration and amount of use (Rosenbaum et al., 2024).

Regular ketamine misuse carries serious long-term health risks, including irreversible bladder damage in over 25% of frequent users.

Frequently Asked Questions About Ketamine and Drug Testing

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Does ketamine show up on a standard 5-panel or 10-panel drug test?

No. Standard 5-panel and 10-panel workplace drug screens do not test for ketamine. A dedicated ketamine panel must be specifically requested. A negative standard drug test does not rule out recent ketamine use.

Can you test positive for ketamine if you received it medically?

Yes. If you received ketamine during a medical procedure or as part of depression treatment, you test positive on a ketamine-specific drug panel for up to several days afterward. Informing the testing party of legitimate medical use beforehand, with documentation, is the correct approach.

What is the difference between ketamine and esketamine (Spravato)?

Esketamine is the S-enantiomer of ketamine — one molecular form of the compound. It is FDA-approved as a nasal spray (brand name Spravato) for treatment-resistant depression and is administered in certified medical settings with monitoring. Recreational ketamine is not pharmaceutical-grade and is often mixed with unknown adulterants, adding additional health risks.

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Can ketamine cause kidney damage?

Yes, in severe cases, ketamine causes kidney damage. Ketamine-induced uropathy can progress from the bladder upward to the ureters and kidneys, causing hydronephrosis (kidney swelling from obstructed urine flow), ureteral scarring, and acute kidney injury. Stopping ketamine early is the primary way to prevent this progression (Baetens et al., 2024).

How long does ketamine stay in your system if you only use it once?

After a single use, ketamine itself clears from the blood within 24 hours. Its metabolites are typically undetectable in urine within 3 to 5 days. Hair testing after a single use shows detectable levels for up to 90 days, though at lower concentrations than with repeated use.

Is ketamine addictive?

Ketamine produces psychological dependence rather than the physical dependence associated with opioids. Regular users develop strong cravings and withdrawal symptoms, including depression and anxiety, when they stop. Addiction treatment that incorporates behavioral therapy and medical support helps manage withdrawal and lower relapse risk.

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Bottom Line

Ketamine is detectable in urine for up to 14 days and in hair for up to 90 days, with chronic users testing positive longer. Beyond detection, regular recreational ketamine use carries serious health risks, especially bladder damage, that are rarely discussed but affect more than one in four frequent users.

If you or someone you love is struggling with ketamine misuse, getting professional support is the most important step. South Carolina Addiction Treatment provides evidence-based detox and residential treatment for substance use disorders in a structured, compassionate setting. You also learn more about our treatment programs to understand what recovery support looks like.

References

Baetens, E., D’Hondt, D., Jacobs, W., Lammens, M., Wood, D., & De Win, G. (2024). Ketamine-induced uropathy: The detrimental effects of chronic ketamine abuse beyond the bladder — a case report with a brief literature review. Journal of Urological Surgery, 11(4), 235–239. https://doi.org/10.4274/jus.galenos.2024.2024-3-13

Belal, M., Kourounis, G., Aldoukhi, A., Castellani, D., Dias, J., Geavlete, B., Gratzke, C., Leow, J. J., Peyronnet, B., Rai, B., Thomas, A., Thursby-Pelham, F., Wood, D., & Rai, B. P. (2024). British Association of Urological Surgeons consensus statements on the management of ketamine uropathy. BJU International, 134(3), 330–343. https://doi.org/10.1111/bju.16404

Katsiari, T., Bae, Y. E., Joseph, D. D. C., Chedid, W. A., Moschonas, D., Kusuma, V. R. M., Patil, K., & Perry, M. J. A. (2024). Newer therapies and surgical management of ketamine-induced uropathy: A review. Therapeutic Advances in Urology, 16, 17562872231208094. https://doi.org/10.1177/03915603231208094

Moeller, K. E., Kissack, J. C., Atayee, R. S., & Lee, K. C. (2017). Clinical interpretation of urine drug concentrations. Mayo Clinic Proceedings, 92(5), 774–796. https://doi.org/10.1016/j.mayocp.2016.12.007

Rosenbaum, S. B., Gupta, V., Patel, P., & Palacios, J. L. (2024, January 30). Ketamine. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK470357/

Staub, C., Jeanmonod, R., & Dubugnon, J. (2018). Systematic review: Analytical methods for hair testing in the context of drug-facilitated crimes. International Journal of Legal Medicine, 132(3), 721–739. https://doi.org/10.1007/s00414-017-1732-1

Zanos, P., Moaddel, R., Morris, P. J., Riggs, L. M., Highland, J. N., Georgiou, P., Pereira, E. F. R., Albuquerque, E. X., Thomas, C. J., Zarate, C. A., & Gould, T. D. (2018). Ketamine and ketamine metabolite pharmacology: Insights into therapeutic mechanisms. Pharmacological Reviews, 70(3), 621–660. https://doi.org/10.1124/pr.117.015198