|Summary sheet: Ketamine|
|Common names||Ketamine, K, Ket, Kitty, "Special K", "Cat Tranquilizer", Ketaset, Ketalar, Ketanest|
|Routes of Administration|
Ketamine (also known as ket, K, special K, kitty, and others) is a classical dissociative substance of the arylcyclohexylamine class. It is the most well-known and widely-used among the dissociatives, a diverse group that includes phencyclidine (PCP), methoxetamine (MXE), dextromethorphan (DXM), and nitrous oxide. It produces its main effects by binding to and blocking the NMDA receptor; however, its precise mechanism is poorly understood and the subject of ongoing research.
Ketamine was developed in 1963 by Parke-Davis Laboratories as a replacement for the surgical anesthetic phencyclidine (PCP). It is widely used in human and veterinary medicine, typically in surgical and intensive care settings. Recently, it has become the subject of significant clinical research due to the discovery that it can rapidly relieve treatment-resistant depression and suicidal ideation. Recreational use is associated with electronic dance music and the club and rave scenes.
Subjective effects include sedation, motor control loss, pain relief, internal hallucinations, conceptual thinking, euphoria, and dissociation. Dissociation is a complex mental state characterized by perceptual distortions and feelings of detachment from the environment and one's self. Ketamine's effects are similar to dissociatives like PCP and DXM but with a shorter duration and rapid onset. The effects of ketamine are highly dose-dependent: at lower doses, users report alcohol-like disinhibition and relaxation effects while higher doses exceeding a certain threshold are capable of inducing a trance-like state (called a "k-hole") that is commonly described as an out-of-body or near-death experience.
Ketamine is considered to have moderate to high abuse potential. Chronic use is associated with escalating tolerance and psychological dependence. Additionally, the physical health effects of chronic use are not well-known. There is growing evidence that chronic use causes bladder and urinary tract dysfunction. Additionally, chronic use has been linked with cognitive impairment which may indicate neurotoxicity. There is also some evidence that it may function as an antibiotic. As a result, it is highly advised to use harm reduction practices if using this substance.
History and culture
Ketamine was first synthesized at Parke Davis Laboratories by the American scientist Calvin Stevens. Stevens was searching for a new anesthetic to replace PCP, which was deemed not suitable for use in humans because of the severe hallucinogenic effects it produced upon recovery of consciousness.
Ketamine began its life as a veterinary anaesthetic when it was patented in Belgium in 1963. After being patented by Parke-Davis for human and animal use in 1966, ketamine became available by prescription in 1969 in the form of ketamine hydrochloride, under the name of Ketalar. It was officially approved for human consumption by the United States Food and Drug Administration in 1970. Due to its sympathomimetic properties and its wide margin of safety, it was administered as a field anaesthetic to soldiers during the Vietnam War.
Ketamine is on the World Health Organization’s “Essential Drugs List”, a list of the safest and most effective drugs needed in a modern health system.
Street names include "Special K", "K", "Kit Kat", "kitty", and "horse/dog/cat tranquilizer" (which refers to its use in veterinary medicine), "Cat Valium", and "Jet".
Ketamine, or (RS)-2-(2-Chlorophenyl)-2-(methylamino)cyclohexanone, is a member of the arylcyclohexylamine chemical class. Arylcyclohexylamines are named for their chemical structures which include a cyclohexane ring bound to an aromatic ring along with an amine group. Ketamine is comprised of a phenyl ring with a chlorine substituent at R2 bonded to a cyclohexane ring substituted with an -Oxo group (cyclohexanone). An amino methyl chain (-N-CH3) is bound to the same location (R1) of the cyclohexanone ring.
Ketamine is a mixture of equal amounts of two enantiomers: esketamine and arketamine. Esketamine is a more potent NMDA receptor antagonist and dissociative hallucinogen than arketamine. Because of the hypothesis that NMDA receptor antagonism underlies the antidepressant effects of ketamine, esketamine was developed as an antidepressant. However, multiple other NMDA receptor antagonists, including memantine, lanicemine, rislenemdaz, rapastinel, and 4-chlorokynurenine, have thus far failed to demonstrate sufficient effectiveness for depression. Furthermore, animal research indicates that arketamine, the enantiomer with a weaker NMDA receptor antagonism, as well as (2R,6R)-hydroxynorketamine, the metabolite with negligible affinity for the NMDA receptor but a potent alpha-7 nicotinic receptor antagonist may have antidepressive action.
Ketamine acts as a non-competitive antagonist of the NMDA receptor, an ionotropic glutamate receptor. NMDA receptors allow for electrical signals to pass between neurons in the brain and spinal column; for the signals to pass, the receptor must be open. Dissociatives close the NMDA receptors by blocking them. This disconnection of neurons leads to loss of feeling, difficulty moving, and eventually the notorious state known as the “K-hole”.
At high, fully anesthetic level doses, ketamine has also been found to bind to μ-opioid receptors type 2 in cultured human neuroblastoma cells without agonist activity and to sigma receptors in rats. Also, ketamine interacts with muscarinic receptors, descending monoaminergic pain pathways and voltage-gated calcium channels. At subanesthetic and fully anesthetic doses, ketamine has been found to block serotonin depletion in the brain by inhibiting 5-HT receptors rather than through monoamine oxidase inhibition.
The estimated bioavailability of rectal ketamine is about 25%, oral ketamine is about 17% while nasal ketamine is 45%.
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), a research literature based on collected anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be regarded with a healthy degree of skepticism. It is worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce a full spectrum of effects. Likewise, adverse effects become much more likely with higher doses and may include addiction, serious injury, or death ☠.
- Sedation - Ketamine is reported to have a moderate sedative effect. It discourages physical activity and can render the user immobile at higher doses.
- Spontaneous bodily sensations - The ketamine "body high" is a sharp, pleasurable tingling sensation which is location-specific to the hands, feet and head. This regularly results in an out-of-body sensation or a general disconnection between the mind and body, which can be accompanied by states of euphoria.
- Physical euphoria - Ketamine can produce states of physical euphoria in some users. However, this effect occurs far less strongly and reliably than opiates or MDMA.
- Perception of bodily lightness - Ketamine produces the sensation that the body is floating and has become entirely weightless. This effect is oddly stimulating, at low to moderate doses, can encourage physical activities by making the body feel light and effortless to move.
- Changes in felt bodily form - Ketamine can strongly alter the way the user perceives their bodily form in a dose dependent manner. At k-hole doses, the user may feel as if they are entirely disconnected from their body.
- Changes in felt gravity
- Motor control loss - A loss of gross and fine motor control alongside balance and coordination is common and becomes pronounced at higher dosages. This means that one should be sitting down before the onset in case of falling over and injuring oneself.
- Tactile suppression - Ketamine partially to entirely suppresses one's sense of touch, creating feelings of numbness within the extremities. It is responsible for the anesthetic properties of this substance.
- Pain relief - Pain relief is very pronounced on ketamine due to its anesthetic properties. Bodily sensations are generally suppressed on ketamine.
- Optical sliding - Ketamine can cause the eyes to wiggle and shake (a condition known as nystagmus), particularly at higher doses. This effect is temporary and usually not a cause for concern unless it persists after other effects have worn off.
- Dizziness - Although uncommon, some people report dizziness while under the influence of ketamine.
- Increased salivation
- Nausea - While uncommon, higher doses of ketamine can sometimes result in nausea and vomiting at the peak of the experience.
- Decreased libido - Unlike stimulants and many other substances, ketamine strongly decreases libido and tends to make sexual activity unappealing and difficult to execute. This effect coincides with tactile suppression and orgasm suppression.
- Gustatory hallucination
- Orgasm suppression - Ketamine strongly inhibits orgasms and the normal sexual arousal response.
- Physical autonomy - Physical autonomy is relatively uncommon, but may occur in some users. Users may feel as if their body is performing gestures and movements outside of their own control. However, it should be noted that these disturbances are relatively simple and short-lived; the typical effect of ketamine is immobilization.
- Physical autonomy
- Difficulty urinating
Ketamine strongly suppresses and distorts one's sense of vision. Do not drive or operate machinery while under the influence of ketamine.
- Double vision - Prevalent at moderate to heavy doses and makes reading text impossible unless closing one eye.
- Pattern recognition suppression - Generally occurs at higher doses and makes one unable to recognize and interpret perceivable visual data.
- Acuity suppression
- Frame rate suppression
The visual geometry produced by ketamine can be described as very brightly colored in scheme when compared to that of other, less visually disconnecting dissociatives like MXE and PCP, but not as complex as the geometry evoked by DXM or any psychedelic. It does not extend beyond level 4 and can be comprehensively described in its variations as: simplistic in complexity, algorithmic in style, synthetic in feel, unstructured in organization, dimly lit in lighting, multicoloured in scheme, glossy in shading, soft in edges, large in size, fast in speed, smooth in motion, equal in rounded and angular corners, immersive in its depth and consistent in its intensity.
Higher doses of ketamine can produce a full range of high level hallucinatory states in a fashion that is less consistent and reproducible than that of many common psychedelics. These effects include:
- Internal hallucination (autonomous entities; settings, sceneries, and landscapes; perspective hallucinations and scenarios and plots) - This effect can be comprehensively described through its variations as delirious in believability, fixed in style, equal in new experiences and memory replays in content, autonomous in controllability and solid in style.
- External hallucination (autonomous entities; settings, sceneries, and landscapes; perspective hallucinations and scenarios and plots) - This effect can be comprehensively described through its variations as delirious in believability, autonomous in controllability and solid in style. The most common theme for this effect to follow is one of experiencing and talking to friends when they are not actually present.
- Analysis suppression - Users report that it is difficult to think normally or logically while under the influence of ketamine. Normal cognition and working memory are impaired in a dose-dependent manner. However, the trade-off is that one's creative or non-linear thinking faculties may become enhanced (see conceptual thinking).
- Anxiety suppression - Anxiety suppression is notable at all doses but not as selective as the effect of benzodiazepines or other GABAergics.
- Cognitive euphoria - Ketamine can produce moderate to strong states of cognitive euphoria which tend to occur during the come-up phase. However, this effect appears to be less pronounced compared to stimulants, entactogens, and opioids.
- Compulsive redosing - Due to its euphoric effects, rapid onset, and short duration, ketamine can cause compulsive redosing in some individuals. It is strongly advised to employ strategies to limit intake and prevent abuse.
- Conceptual thinking - Ketamine produces conceptual or non-linear thinking in a manner that can stimulate one's artistic or creative faculties. Users commonly report entering dream-like, highly complex and abstract mental spaces while under the influence of ketamine. Many users describe ketamine as freeing one from the boundaries of normal cognition, which may promote new insight into their lives and mental patterns.
- Déjà vu - Ketamine can produce powerful sensations of déjà vu, moreso than other substances.
- Delusion - Delusions appear to occur more commonly on ketamine than other substances (e.g. stimulants, psychedelics). This effect often coincides with the ego inflation component of ketamine. It is strongly advised to avoid ketamine if you are susceptible to mental disorders like schizophrenia or bipolar disorder as it may exacerbate delusions and trigger psychosis.
- Depersonalization & Derealization
- Disinhibition - Low doses of ketamine produce disinhibition in a similar manner as alcohol. As a result, it is sometimes used for this purpose in parties and raves. Higher doses will result in the opposite effect: social withdrawal and inability to communicate normally.
- Dream potentiation
- Ego inflation - Lower doses of ketamine may result in ego inflation similar to that observed on alcohol, benzodiazepines, or cocaine.
- Focus suppression - Ketamine strongly suppresses the ability to focus on a single task or object. Its mental effect can be described as "scattering" and "non-linear". Occurs alongside analysis suppression.
- Immersion enhancement - Ketamine markedly enhances one's sense of immersion, particularly when viewing visual media. It is considered to be one of the most immersion-enhancing substances known.
- Increased music appreciation - Ketamine may increase one's appreciation of music depending on dose and setting. However, this effect is generally less consistent than the effect of psychedelics or entactogens. Sometimes the opposite effect occurs and causes music to sound alien and unpleasant.
- Introspection - Some user reports suggest ketamine may enhance introspection; however, this effect appears to be much less consistent and robust than psychedelics, entactogens, and stimulants. It should be noted that there is limited evidence showing ketamine has psychotherapeutic benefits.
- Memory suppression - Ketamine strongly suppresses short and long-term memory (in a dose-dependent manner) for the duration of the experience. Heavy doses appear to be able to temporarily turn off one's memory altogether and produce amnesia.
- Personal bias suppression - Some user reports suggest ketamine may suppress one's personal bias; however, this effect appears to be much less consistent and robust than the effect of psychedelics or entactogens. It should be noted that there is currently limited evidence showing ketamine has psychotherapeutic benefits.
- Psychosis - Psychosis appear to be more common on ketamine than other substances (e.g. stimulants, psychedelics). This effect often coincides with the delusion component of ketamine. It is strongly advised to avoid ketamine if you are susceptible to mental disorders like schizophrenia or bipolar disorder as it may exacerbate delusions and trigger psychosis.
- Spatial disorientation - Spatial orientation is very prominent on ketamine and occurs in a dose-dependent manner. As a result, the user should carefully analyse any environment in which they are taking ketamine to avoid becoming lost or injuring themselves.
- Suggestibility enhancement - The user may be rendered significantly more suggestible during and after ketamine administration. This may be a result of ketamine's effect on cognition and susceptibility to delusions and psychosis.
- Thought deceleration - Thoughts may be generated and perceived by the user as if they are stiff, frozen, or in slow-motion. Ketamine and dissociatives are known to produce this effect more strongly than other substances.
- Time distortion - Ketamine significantly alters the subjective passage of time, particularly at the k-hole threshold. In this state, the user is largely unable to tell how much time has passed; some users report that it can feel like an entire lifetime in the span of half an hour. Some report being transported to a place seemingly beyond time and space until the effects wear off.
- Ketamine is widely known for its disconnective effects, which together can be referred to as "dissociation". The following lists a breakdown of the different forms of sensory and mental disconnection reported on ketamine.
- Synaesthesia - Synaesthesia is sometimes reported on ketamine, especially at higher doses. Some users have reported the experience of being able to "hear colors" or "see sounds" in the k-hole state. However, it is not clear if ketamine is capable of producing synaesthesia as a normal effect or if it is merely eliciting it in predisposed individuals. More research is needed to understand the etiology of this reported effect.
- Transpersonal effects are sometimes reported on ketamine and other dissociatives. However, these effects appear to occur with far less consistency and robustness than those observed on psychedelics and entactogens. It should be noted that there is currently limited clinical evidence that ketamine has psychotherapeutic benefits and some evidence that it promotes disordered thinking.
Anecdotal reports which describe the effects of this compound within our experience index include:
- Experience: 500 mg Ketamine (Insufflated) - A Nauseating Voyage Through Parallel Universes
- Experience:260 mg Ketamine (insufflated) - Lost in Paisley
- Experience:300mg Ketamine (Insufflated) - The Void: Finding peace in death
- Experience:50mg Ketamine (esketamine) i.m. - Exploring space heights and ocean depths
- Experience:75mg Ketamine (insufflated) - Wandering through the winter night
- Experience:Date: MM/YYYY Age: Sex: Height: Weight: kg / lb (include both if possible) Misc:
- Experience:Ketamine (200mg nasal) Quasi sexual experience
- Experience:Ketamine (unknown dosage) - States of unity and interconnectedness
Additional experience reports can be found here:
Ketamine has been shown to be effective for patients suffering from chronic depression and bipolar disorder. Studies have shown that the effect of the drug is immediate or within 2 hours and consistent in relieving a patient’s depressive and/or suicidal symptoms, lasting up to 3 days after a single dose. In comparison, common antidepressants such as Prozac can take weeks to show effects. This gives ketamine the potential to become an indispensable tool in the treatment of depression and bipolar disorder, which is currently being held back by institutionalized drug prohibition.
Ketamine is a racemate that comprises the R-(−)-ketamine enantiomer (arketamine) and the S-(+)-ketamine enantiomer (esketamine). Esketamine inhibits the reuptake of the dopamine transporter about 8-fold more potently than does arketamine, and so is about 8 times more potent as a dopamine reuptake inhibitor. Arketamine appears to be more effective as a rapid-acting antidepressant than esketamine.
A study conducted in mice found that ketamine's antidepressant activity is not caused by ketamine inhibiting NMDAR, but rather by sustained activation of a different glutamate receptor, the AMPA receptor, by a metabolite, (2R,6R)-hydroxynorketamine; as of 2017 it was unknown if this was happening in humans. Arketamine is a AMPA receptor agonist.
Anesthetic doses may not produce an antidepressant effect. While the research is limited, between .5 and 1mg/kg IV given over about 40 mins seems to be the optimal dose.  A typical anesthetic dose is 1-2 mg/kg given over 2 minutes, followed by .5-1.8mg/kg/hr. Benzodiazepines and GABA agonist (both of which are often used alongside ketamine in anesthesia) may mitigate the antidepressant effect of ketamine.
Exposing compounds to the reagents gives a colour change which is indicative of the compound under test.
|No reaction||No reaction||Deep brownish orange/red||Light yellow||No reaction||No reaction||No reaction|
|No reaction||No reaction||Orange - Pink - Yellow||Slow pink||No reaction||No reaction|
Toxicity and harm potential
Cognition and well-being
The first large-scale, longitudinal study of ketamine users found that frequent ketamine users (at least 4 days/week, averaging 20 days/month) had increased depression and impaired memory by several measures, including verbal, short-term memory and visual memory. However, infrequent (1–4 days/month, averaging 3.25 days/month) ketamine users and former ketamine users were not found to differ from controls in memory, attention and psychological well-being tests. This suggests the infrequent use of ketamine does not cause cognitive deficits and that any deficits that might occur may be reversible when ketamine use is discontinued.
However, abstinent, frequent, and infrequent users all scored higher than controls on a test of delusional symptoms.
Urinary tract effects
According to a 2010 systematic review, 110 documented reports of irritative urinary tract symptoms from ketamine dependence exist. Urinary tract symptoms have been collectively referred to as "ketamine-induced ulcerative cystitis" or "ketamine-induced vesicopathy" and they include urge incontinence, decreased bladder compliance, decreased bladder volume and painful haematuria (blood in urine).
The time of onset of lower urinary tract symptoms varies depending, in part, on the severity and chronicity of ketamine use; however, it is unclear whether the severity and chronicity of ketamine use corresponds linearly to the presentation of these symptoms. All reported cases where the user consumed greater than 5 grams per day reported symptoms of the lower urinary tract.
A study conducted in 2015 demonstrated that co-administration of EGCG (10mM/kg) in rats receiving daily dose of Ketamine (25 mg/kg/d), significantly reduced Ketamine-induced bladder damage to almost control levels, showing potential benefits of EGCG consumption to prevent or reverse ketamine-induced cystitis (KIC) and ovariectomy-induced overactive bladder (OAB).
Short-term exposure of cultures of GABAergic neurons to ketamine at high concentrations led to a significant loss of differentiated cells in one study, and non-cell death-inducing concentrations of ketamine (10 μg/ml) may still initiate long-term alterations of the dendritic arbor in differentiated neurons.
More recent studies of ketamine-induced neurotoxicity have focused on primates in an attempt to use a more accurate model than rodents. One such study administered daily ketamine doses consistent with typical recreational doses (1 mg/kg IV) to adolescent cynomolgus monkeys for varying periods of time. Decreased locomotor activity and indicators of increased cell death in the prefrontal cortex were detected in monkeys given daily injections for six months, but not those given daily injections for one month.
Dependence and abuse potential
Ketamine has moderate to high abuse potential and produces psychological dependence with chronic use. When dependence has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.
Tolerance to the main effects of ketamine develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Ketamine presents cross-tolerance with all dissociatives, meaning that after the consumption of ketamine all dissociatives will have a reduced effect.
It is strongly advised to use harm reduction practices if using this substance.
Dissociatives are reported to be unique from other substances because they produce a long-term or permanent form of tolerance ("permatolerance") that accrues slowly and independently from normal tolerance. Many long-term or heavy ketamine users report that they need to take substantially more to achieve dissociation or k-hole compared to their first use, even after taking extended breaks. It is unknown why or how this occurs, although it has been suggested to be a potential indicator of some form of neurotoxicity. Dissociative permatolerance can pose an additional problem considering the negative effects of large doses on the urinary tract. As a result, heavy or chronic use of all dissociatives is strongly discouraged.
Fatal ketamine overdoses are particularly rare, but not unheard of. However, the exact toxic dosage is unknown.
Although many psychoactive substances are reasonably safe to use on their own, they can suddenly become dangerous or even life-threatening when combined with other substances. The following list includes some known dangerous combinations (although it is not guaranteed to include all of them). Independent research (e.g. Google, DuckDuckGo) should always be conducted to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
- Amphetamines - No unexpected interactions, though likely to increase blood pressure but not an issue with sensible doses. Moving around on high doses of this combination may be ill-advised due to risk of physical injury.
- Cocaine - No unexpected interactions, though likely to increase blood pressure but not an issue with sensible doses. Moving around on high doses of this combination may be ill-advised due to risk of physical injury.
- Benzodiazepines - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position.
- MAOIs - MAO-B inhibitors appear to increase the potency of ketamine. MAO-A inhibitors have some negative reports associated with the combination but there isn't much information available
- Alcohol - Both substances cause ataxia and bring a very high risk of vomiting and unconsciousness. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position.
- GHB - Both substances cause ataxia and bring a risk of vomiting and unconsciousness. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position.
- GBL - Both substances cause ataxia and bring a risk of vomiting and unconsciousness. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position.
- Opioids - Both substances bring a risk of vomiting and unconsciousness. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position.
- Trazodone - When used as a sleep aid and taken close to that of a dose of ketamine, may bring a risk of respiratory depression when high amounts of each substances are consumed.
- Grapefruit - Grapefruit juice significantly increases oral absorption of ketamine. This may result in the user having double the concentration of ketamine in their system compared to normal. The ketamine may also have a longer duration of effect. This is likely to apply to oral, sublingual, and intranasal administration.
- Australia: Ketamine is a Schedule 8 drug in Australia, meaning that possession, manufacture or supply without authority is illegal.
- Austria: Ketamine is legal for medical and veterinary use and illegal when sold or possessed without a prescription under the NPSG (Neue-Psychoaktive-Substanzen-Gesetz Österreich).
- Belgium: Ketamine is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
- Brazil: Ketamine is legal for veterinary use and illegal when sold or possessed for human use.
- Canada: Ketamine is controlled under Schedule I of the Controlled Drugs and Substances Act. Activities such as sale, possession or production of ketamine are illegal unless authorized for medical, scientific or industrial purposes. In Canada, ketamine has legitimate uses in medicine.
- China: Ketamine is a Schedule II drug.
- Czech Republic: Ketamine is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
- Denmark: Ketamine is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
- France: Ketamine is a Schedule IV drug in France.
- Germany: Ketamine is a prescription medicine, according to Anlage 1 AMVV.
- Hong Kong: Ketamine is a Schedule I drug in Hong Kong.
- Luxembourg: Ketamine is a prohibited substance for recreational use.
- Malaysia: Ketamine is illegal to sell and possess in Malaysia.
- Mexico: Ketamine is a Category 3 drug in Mexico.
- New Zealand: Ketamine is a Class C drug in New Zealand.
- Norway: Ketamine is a Class A drug in Norway.
- Singapore: Ketamine is a Class A drug in Singapore.
- Slovakia: Ketamine is a Schedule II drug in Slovakia.
- South Korea: Ketamine is illegal to possess and sell in South Korea.
- Spain: Ketamine is a Schedule IV drug in Spain.
- Sweden: Ketamine is a Schedule IV drug in Sweden.
- Switzerland: Ketamine is a controlled substance specifically named under Verzeichnis B, when possessed or handled without a license. Medicinal use is permitted.
- Taiwan: Ketamine is a Schedule III drug in Taiwan.
- Turkey: Ketamine is a 'green prescription' only substance and illegal when sold or possessed without a prescription.
- United Kingdom: Ketamine is a Class B drug in the United Kingdom.
- United States: Ketamine is a Schedule III drug in the United States.
- Poland: Ketamine is illegal to possess, manufacture and sell except for medical purposes. 
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