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Ketamine FAQ
by Erowid
v2.11 - December 2015 (v1 Dec 1994)
Citation:   Erowid. "Ketamine FAQ 2.1". Dec 2014. Online edition:
The following is roughly based on a 1994 FAQ concerning the recreational use of ketamine hydrochloride. Information contained herein was compiled from scientific references and user anecdotes, but it may contain incomplete or out-of-date information and the authors are not responsible for anyone's misinterpretations or misuse of ketamine as a result of reading this material. This information may be shared as an educational document provided this disclaimer is included and the contents and authorship information of the FAQ are delivered intact.

WARNING: Since the late 1990s, especially in Europe, several other chemicals (including heroin, cocaine, and MDMA) have been sold as "ketamine". Sometimes these chemicals are mixed with ketamine and sometimes ketamine is mixed with a non-psychoactive filler. Impure drugs and unknown combinations of drugs can be dangerous and for this reason it is generally a bad idea to obtain ketamine (or any other recreation drug) in a rave or club setting. This FAQ focuses on the use of pharmaceutical-grade ketamine hydrochloride and does not address the issues that arise when obtaining material of an unknown potency or purity.

Name of Drug #
Ketamine Hydrochloride

Street Names #
K, ket, special K, vitamin K

Chemistry # 1
2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone hydrochloride
Molecular Weight: 274.2
Melting Point: 266 degrees C
White solid; non-flammable
LD50: (IPR-MUS): 400 mg/kg; (IVN-MUS): 77 mg/kg
Soluble in water 20 g/100 ml

What is Ketamine? #
Ketamine HCl is an anaesthetic used in both human and veterinary medicine. It blocks nerve paths without significantly depressing respiratory and circulatory functions. In pure form it is a crystalline solid.

When used in a medical context, ketamine is usually injected intramuscularly (IM) or intravenously (IV) in liquid form. It is less commonly available from compounding pharmacies as a transdermal cream for treating neuropathic pain syndromes (such as shingles) and as a sublingual lozenge used for treating breakout pain.

Pharmaceutical ketamine is generally available in two strengths: 50 mg per ml, and 100 mg per ml. Its most common trade names are Ketaset and Ketalar, but there are many other brands. Some contain additional potentially psychoactive chemicals, such as benzthonium chloride or chlorobutanol.

In addition to its use as an anaesthetic, ketamine has also found some utility in treating other indications such as addiction,2 depression,3 rabies,4 and in psychedelic psychotherapy.5

When used in a recreational context, ketamine is usually injected IM or insufflated (snorted). It is less often consumed orally, and even more rarely used rectally. Its legal status varies around the world. Since 1999/2000, many countries have implemented additional legal controls on possession such as scheduling it or making it available by prescription only.

What Are Typical Ketamine Dosages? #
Ketamine can produce wide-ranging effects from different dosages. Some people enjoy lower doses in more social contexts such as dancing while others prefer stronger psychedelic experiences while lying down. There seems to be a crucial line where the dissociative effects assert themselves and a person loses grasp of his or her primary senses. A further line exists where the user completely loses consciousness. Boosting (taking one or more additional doses after the initial dose) is quite common, especially with insufflated ketamine, with some people choosing to use low doses at frequent intervals. Tolerance is appreciable, with some users reporting that several weeks are required between uses to again achieve full effects from a given dose. For most people, effects are linear with dose, and positive experiences can be achieved from low doses.

Injected (IM):
Intramuscular (IM) doses for psychedelic effects begin at approximately 0.3-0.4 mg/lb (0.66-0.88 mg/kg). Fully anaesthetic IM doses are about 1 mg/lb (2.2 mg/kg). Due to the volume of liquid when using 50 mg/ml material, two injections are usually made instead of one. Sterility of the material and the needle are imperative. Most people obtain psychedelic effects at an IM dose of 100 mg. Some users report soreness at the injection site(s) for several days or weeks; such soreness is minimized when users relax the muscle being injected into, and when the injection is made slowly, taking 15-30 seconds to push a ml or less of liquid.

Intravenous (IV) injection is not recommended: rapid IV injection can cause the user to stop breathing, while slower IV injection can cause a self-injector to lose consciousness with a needle left in his or her vein before the injection is complete, possibly resulting in bleeding that continues until self-awareness has returned.

Insufflated (Snorted):
A solid insufflated dose is around 0.5-1.0 mg/lb (1.1 - 2.2mg/kg). A lower, more social nasal dose that still produces distinct effects would be around 0.25 mg/lb (0.55mg/kg), with low doses producing shorter and milder effects. One technique users employ is to consume one "bump" of powdered ketamine up each nostril every few minutes using a "bullet"-style device until desired effects are reached. Some users report that smaller amounts taken in this way work better than snorting a large line all at once. Presumably the reason for this relates to better absorption in the nose when taken over time, whereas when it is consumed all at once some of it is lost down the back of the throat via post-nasal drip. Compared to many other commonly snorted recreational drugs, ketamine is relatively comfortable in the nasal region; however, many people dislike the taste if/when it begins to drip down the back of their throats.

Common oral dosages are around 1.0-2.0 mg/lb (2.2 - 4.4 mg/kg). Anaesthetic oral doses begin at around 4.0 mg/lb (8.8 mg/kg). A maximum oral dose of 3 mg/lb (6.6 mg/kg) should be set in order to allow for adequate recovery. Increasing oral dosage above 1.0-2.0 mg/lb (2.2-4.4 mg/kg) yields little psychedelic advantage and can result in greater temporary memory loss. A minimum dose of around 150-175 mg may be required for a psychedelic experience. Higher oral doses have rapidly diminishing returns over lower doses, resulting in stomach upset, greater temporary memory loss, and little psychedelic advantage.

Rectal doses range from 0.6 mg/lb to 3.5 mg/lb (1.3-7.7 mg/kg), but the higher doses can produce extremely strong effects, and some users report strong effects even from the lighter end of this dose range. Rectal doses tend to last substantially longer than other means of administration.

How is Ketamine Prepared for Administration? #
Safely taking doses by injection requires sterile liquid ketamine and a clean/new single-use needle. (Reusing or sharing needles can spread diseases.) Liquid ketamine is sometimes converted into powder for nasal or oral use by gently boiling off the solution or by pouring the material into a glass baking dish and subjecting it to short bursts in a microwave until the liquid has evaporated. Oral doses are prepared by placing powder into a cup, adding about 1 cm of hot water, and stirring the material to dissolve it; the remainder of the cup can be filled with juice and the mixture drunk.

In What Settings Do People Take Ketamine? #
The setting people prefer is heavily dependent on dose and method of administration. Lower doses that still permit some level of walking, dancing, and talking can be used in real-world social scenes, i.e. clubs, parties or other gatherings. Higher doses are generally taken only while lying down in a safe space.

As with many anaesthetics, ketamine can cause varying degrees of nausea, usually related to dose. To reduce the likelihood of nausea, food is not generally consumed within ninety minutes before the trip, and is avoided for longer periods of time if possible. While vomiting is rare, travelling to the bathroom is no fun, as movement can increase nausea. Cautious users may keep a bucket available as a precaution. Some people find cannabis helpful to quell nausea. Experienced higher-dose ketamine users situate themselves in a place where they can stay for several hours, with any desired amenities close at hand. A sober sitter is convenient for changing music, providing sips of water, and generally making sure everything is going smoothly. Complete darkness can eliminate some strange and unique visual experiences, so many users prefer to take ketamine in a dimly lit room.

Music can be powerful for "driving" the trip, with individual tunes helping to create visionary vignettes. However, ketamine does not treat audio perception so well; it may produce a narrowing of the user's aural bandwidth. Many users choose mellow instrumental music with a psychedelic flavor, and they keep the sound level down a bit as music can sound louder when under the influence. Touch can be exceptional, and some swear by the benefits of receiving massage therapy and bodywork while on ketamine. Smells and tastes are usually reported as being dulled. Some users find they are largely unable to talk, while others speak in clipped, robotic-sounding utterances. Mental reflection and introspection is fairly common, but enhanced emotionality much less so. Physical warmth may be important to attend to, as users can become cold from inactivity. Many users take ketamine while lying in bed, with a blanket nearby.

How Long Does Ketamine Last? #
Taken via IM injection, ketamine's effects may start to be felt in less than 2 minutes. Nasal doses require 5-10 minutes to take effect. On an empty stomach, effects from an oral dose may start in as little as 5 minutes, but with a medium-full stomach, it may take 15-60 minutes or longer before they begin. The coming-up period as effects kick in is fast but generally not considered too frightening. Typically, higher-dose users experience semi-consciousness for about 30-45 minutes when insufflated, for about 45-60 minutes when taken IM, for about 90 minutes when taken orally, and for about 2 hours when used rectally. They may feel light, lanky, and/or queasy for several hours, and may be somewhat dizzy, though not incapacitated the following day.

What is Ketamine Like at Lower Doses? #
People report mild inebriation, dreamy thinking, stumbling, clumsy, or "robotic" movement, delayed or reduced sensations, vertigo, increased sociability, and an interesting sense of seeing the world differently. Nausea and vomiting can result even from lower doses.

What is Ketamine Like at Higher Doses? #
Initially, a sort of fragmentation of reality may occur. Some users report that their environment seems to begin spinning, but not in a bad "alcohol spins" sort of way. Chaos may then ensue. At some point, at higher doses, many users find themselves completely removed from their surroundings and their bodies. Descriptions of the experience vary substantially, but many include talk of alternate planes of existence, a sense of movement through a space or landscape, a oneness with everything, past and future revelations, and strange fabrics or textures of all sorts. Many users have difficulty communicating during the peak of the effects, and they may not be able to see or hear others in the room. Revelations can be extremely heavy or frightening, but usually the fear does not dominate re-entry and it is therefore difficult to remember it as "scary". Some users describe the feeling of coming back across the "reality" line in a visual way, attempting to put an object in focus or define it. It is at this point that they may try to get in touch with their co-trippers. This is the "wow" period. The wise user does not try to move for a while at this point, as the experience continues mildly for an hour or so after this, with an increasingly conventional focus.

What are Some Precautions to Consider? #
An overdose of ketamine will knock a person out as if they were in an operating room having surgery. Most users consider this to be a waste of their tripping experience, especially as it can make them sick to their stomachs. While fatalities caused by the direct pharmacological effects of ketamine are nearly unheard of at normal recreational doses, ketamine is a powerful anaesthetic and being anaesthetized, semi-conscious, or unconscious carries distinct risks. Body positions that restrict breathing or blood-flow (e.g. "child's pose" or face down into a pillow) can result in serious injury or death even if the person is conscious.

Extreme care should be taken before combining ketamine with respiratory depressants such as alcohol, GHB, opiates, barbiturates, and/or benzodiazepines. This can be very dangerous. While most (if not all) of these combinations have been used without negative incident, this does NOT mean that they should be considered safe. Opiates/opioids such as heroin are potentiated by ketamine even at low doses, with a consequent risk of respiratory depression. Ketamine is often described as being used at low insufflated doses during or following the use of psychedelics and stimulants such as 2C-B, 5-MeO-DMT, cocaine, dextromethorphan, DMT, LSD, methamphetamine, MDA, MDMA, nitrous oxide, and many other drugs. While negative physical reactions are rarely reported, negative psychological reactions have been described in some cases with assorted combinations.

Since ketamine can produce subconscious or unconscious states, it should never be used in proximity to open flames (candles, fireplaces) due to the risk of accidental fires. It should also never be used in proximity with water (bathtubs, hot tubs, pools) due to the risk of drowning. Accidents and at least one death have been reported in cases where ketamine and fire or water were combined in close proximity. Inexperienced trippers may be overwhelmed by the awesome revelations that can be experienced on ketamine, although fear and paranoia are much less commonly reported in comparison to other psychedelics, and will probably be only episodic. A peculiar sort of loneliness can occur once a ketamine user is "over the line", so careful psychonauts keep good friends, a sober sitter, or an experienced ketamine user nearby.

What Else Do People Report About Ketamine? #
Some sources characterize ketamine as a boring drug. Some users complain that it removes them so completely from their bodies that it is difficult to work with. Others have found ketamine to be potent and malleable: an experience that they can tailor by paying close attention to the dose and setting. Many ketamine users experience ketamine as compellingly unique among psychedelic drugs, although PCP, DXM, nitrous oxide, and Salvia divinorum are the most commonly made comparisons. Users sometimes express that the high-dose experience is unique and strong enough that only experienced trippers who want a potentially life-changing out-of-body experience should attempt high doses. Ketamine is often described as having a good recovery time, with little negative effect on the following day--perhaps only a mild hangover.

Although most ketamine sold is a racemic mixture, meaning that it contains equal parts of the S(+) and R(-) enantiomers, there is also some ketamine available that is entirely comprised of the S(+) enantiomer. The S(+) enantiomer is more likely to produce a loss of consciousness and is a better painkiller. Some recreational users prefer the racemic mix, while others prefer the S(+) enantiomer.

Can Ketamine Use Have Negative Health Effects? #
The answer to this question for any drug is a clear yes. Any substance or food can be over used to the point where it can cause physical damage or dysfunctional psychological dependence in at least some people. The primary negative health effects associated with ketamine are accidents that happen when people are under the influence (falls, burns, etc); life, work, and social problems related to frequent use; inability to control the dose and frequency of use ('compulsive use'); damage to nasal passages from frequent insufflation; possible injection-site infections from IM and IV use; and lasting urinary tract damage and pain.

Compulsive Use:
Problems with addiction and habituation have been reported by people who have access to a steady supply of ketamine. Problematic use is sometimes accompanied by paranoia, an increase in the sense of synchronicity in daily experiences, and egocentrism (the world revolves around the user). With compulsive use, a user may also have impaired judgment with respect to what activities or contexts are appropriate while under the influence (e.g. driving a car, going to a job, or taking a bath), which can increase the risk of accidents. As with any addictive substance, it's a good idea to set hard limits about maximum use and types of use before it becomes a problem.

Urinary Tract Problems:6
Some ketamine users report severe abdominal pain after heavy use. Frequent ketamine use has been associated with urinary tract symptoms that can include increased frequency of urination, urinary incontinence, pain during urination, passing blood in the urine, and reduced bladder size. In several reported severe cases, surgical intervention to remove the bladder was deemed necessary by clinicians. The wide dose-response range leading to documented cases suggests that individual responses to ketamine may be idiosyncratic and unpredictable, making it unclear what level and frequency of use may lead to urinary problems. Nevertheless, frequent ketamine users may want to cut back on their use, and all ketamine users might want to moderately increase their intake of water and pay attention to even minor urinary symptoms.

Aren't There New Versions of Ketamine Available? #
Substances similar to ketamine like tiletamine and the research chemical methoxetamine are not "types" or forms of ketamine; they are completely different drugs that have their own effects profiles, risks, and benefits. There are several other drugs that are NMDA-receptor antagonists, including DXM, tiletamine, methoxetamine, and others.

References #
  1. # The Merck Index, Eleventh Edition (entry no. 5174, p. 834). 1989.
  2. # Krupitsky EM, Burakov AM, Dunaevsky IV, et al. "The Combination of Psychedelic and Aversive Approaches in Alcoholism Treatment: The Affective Contra-Attribution Method." Alcoholism Treatment Quarterly. 1992;9(1).
  3. # Zarate Jr CA et al. "A Randomized Trial of an N-methyl-d-aspartate Antagonist in Treatment-Resistant Major Depression", Arch Gen Psychiatry. 2006;63(8):856-864.
  4. # Willoughby Jr RE. "A Cure for Rabies?" Scientific American. Mar 18, 2007.
  5. # Krupitsky EM, Kolp E. "Ketamine Psychedelic Psychotherapy." In Psychedelic Medicine. Winkelman MJ, Roberts TB. ed. Praeger/Greenwood Publishers. 2007.
  6. # Hanna J. "KLUTS: Ketamine and Lower Urinary Tract Symptoms." Erowid Extracts. Nov 2010;19:12-4.
  7. # Anis NA et al. "The Dissociative Anaesthetics, Ketamine and Phencyclidine, Selectively Reduce Excitation of Central Mammalian Neurones by N-Methyl Aspartate", Br J Pharmacol. 1983;79(2):565-575.
  8. # Jansen K Ketamine: Dreams and Realities. MAPS. 2004.
Revision History #
  • v1.0 - Dec 1994 - No Author Listed - Original published version of Ketamine FAQ
  • v2.0 - August 2011 - Erowid - Major Rewrite. Corrected assorted typos; improved the language; reorganized; changed tone; added description of medical uses; added mention of rectal use; added information about chemicals commonly included in pharmaceutical ketamine; added information related to techniques for avoiding injection soreness; added specifics related to problems from IV injection; added a reportedly more effective technique for intranasal use and comment about bad taste via the nasal route; added note on microwave prep for powder from liquid; removed suspect comment about nitrous oxide bringing ketamine users down more quickly; added precautions about fire and water; added more details related to known combinations; updated precautions section regarding heroin; removed erroneous statement about ketamine not having a "build-on effect with hallucinogens"; removed some redundant text; corrected references; added new references. Added health concerns section, added section about other arylcyclohexylamines.
  • v2.1 - December 2014 - Erowid - Minor updates
  • v2.11 - December 2015 - Erowid - Fixed errors with mg/lb to mg/kg conversion. Math was wrong, making the mg/kg doses too low.