Ketamine is a dissociative anesthetic commonly used in humans. It has a very wide safety margin, with a "therapeutic" dose being as much as ten times a "recreational" dose in a naive user.
Ketamine is generally sold to the recreational user in one of two forms: in the evaporated salts, which are sold as a powder, or crystals called shards, as well as in the multi-dose vials for use in veterinary and human medicine. These latter vials may have concentrations of 5mg/mL all the way up to 100mg/mL, and vary by manufacturer. One manufacturer, Parke-Davis there are cases of accidental overdoses of ketamine as much as ten times higher than that required for surgery (which is to say 40-100x a recreational dose) "with no obvious, lasting effects." It is therefore reasonable to consider it a drug of relatively safe usage.
Because ketamine is a dissociative and an anesthetic, users are prone to becoming injured by interaction with their environment and have died from e.g., drowning (DM Turner). Overdose, however, is unlikely.
Ketamine is usually used either injected intramuscularly (although intravenous administration does happen) or insufflated. Additional routes of administration are "plugging" (rectal) and orallyRoute of administration in which the subject swallows a substance.. Oral availability of ketamine is poor.
In some countries, such as Thailand and Mexico, ketamine is available over-the-counter without a prescription; legality for human use is questionable, however.
Ketamine was originally produced by Sandoz laboratories in the early 1960s, and its recreational use was first reported in 1965; by the early 1970s, the US FDA was concerned about its use as a recreational drug. In the early 1990s, the US "Drug Czar" labeled ketamine as an "emerging drug" because of its involvement in the electronic music scene, and by 1999, it had been scheduled in the United States (Sched III), although this designation is only applicable when the drug is intended for use in humans.
These numbers are quoted directly from Erowid (which uses subjective dosage reports…). Individual dosages will vary based on route of administration, tolerance of the user, purity of the drug, weight of the user, and other conditions. It is always wise to start with a small dose and work up to a recreational dose. Remember, you cannot take less of the drug you have taken, but you can always take more.
There is no "guaranteed" dose to "hole" with ketamine. The "k-hole" as it is called is a state of full dissociative anesthesia in which the user is able to retain a semblance of consciousness. The effect associated with this is ego death; that is, the dissolution of the ego, the loss of the perspective of "I" in perception. It is a tricky dose to attain. Reaching too far with dosage will result in full anesthesia without memory of the experience and is worthless for recreational or psychonaut purposes. Too low a dosage will result in a mild sedation and body load, but no ego death, and redosing when anesthetized is tricky.
It is posited that using a needle and a precisely measured dose is more likely to get a user to a full state of ego death, the k-hole, due to the lack of titration of dosage, rapid come-up, and exactly-metered dosage. Finding a dosage that "works for you" is important, and there will need to be a period of experimentation before such a dose is found. Assuming the user does not approach this dose very often, tolerance should not build, and it can be consistently used to reach that level of effect/ego death.
It may be helpful for the user to measure out doses in syringes before using if a re-dose is desired; pulling a new shot can be difficult while under the effects of ketamine, and takes time while the drug is wearing off. Administering a shot while anesthetized can be perilous at best; for this reason, re-dosing is not recommended. If one must re-dose, use of an "auto-ject" like device (a spring loaded syringe) is convenient.
Because the "k-hole" involves full dissociative anesthesia, it is crucial that the user be in a safe place, physically, such as lying flat in bed. It may be useful to have a sitter present because arousal from the k-hole may be disorienting.
Understand, however, that there is no guaranteed mechanism for "reaching the hole," and it takes practice. Become familiar with the drug before taking heroic doses. Find a dose that works for you.
1-4mg/lb of body mass. Doses higher than 3mg/lb may exceed the recreational window and leave the user anesthetized rather than "tripping." Doses of 2-3mg/lb may incur greater (short-term) memory loss and have little additional value as a psychedelic.
Threshold effects may begin about 1/4mg/lb body mass, and recreational doses can range up to 2mg/lb. As above, higher doses may not yield greater desirable effect. Ketamine is reported to be fairly gentle on the nasal tissues compared to brominated phenethylamines and organofluorides.
Typically 1mg/lb body mass for IM injection is quite sufficient for a full dissociative experience. Doses of .5-.75mg/lb are more "threshold" and cogent experiences. Doses exceeding 1mg/lb body mass usually result in full anesthesia with little recall of the experience and may take longer to recover. There may be short-term memory loss with higher doses.
Onset: < 2 minutes. Duration: major effects < 60 minutes; tertiary effects 90 minutes; return to baseline 120 minutes.
Intravenous injection is possible with ketamine. The doses are the same as for intramuscular injection. However, with intravenous injection, the user can become fully anesthetized before she is able to remove the needle from her body. For this reason alone intravenous injection of ketamine is discouraged. Additionally, intramuscular injection provides a near-identical experience with the only major difference being a shorter (< 1 minute vs < 2 minutes) come-up.
It is assumed that ketamine provided is simply the evaporated shards of veterinary-grade ketamine (e.g., Ketalar, Ketaset, etc). These instructions do not cover "extraction" of ketamine from non-ketamine-containing mixtures. Additionally, the assumed route of administration here is intramuscular, not intravenous; intravenous solutions can have a higher concentration of ketamine per ml.
Ketamine is quite soluble in water up to about 200mg/ml when warm and closer to 100mg/ml at room temperature.
Always use a test injection of e.g., 1/10th cc (in this case, 10mg) before actually using a therapeutic or recreational dose.
Benzyl benzoate may be used instead of benzyl alcohol at 1-2% per volume as a preservative/antimicrobial agent.
Ketamine is highly soluble at room- and body temperature. That said, for intramuscular injection, it is very important to ensure the solution will not "crash" (come out of solution) post-injection because of the solution cooling. Under no circumstances should you prepare a solution of greater than 100mg/ml or inject a solution that is above body temperature.
With benzyl alcohol or benzyl benzoate, in sterile sealed vials, having been processed through a syringe filter, and kept above freezing, this solution should remain quite stable and sterile indefinitely.
Controlled in the United States via the Federal Analog Act but only if it is intended for human consumption.