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Psychedex
Facts label

Ketamine Facts

Dissociative; Arylcyclohexylamine; NMDA receptor antagonist

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 50 mgLight50 – 100 mgCommon100 – 200 mgStrong200 – 300 mgHeavy300+ mg

Starts in 15 – 30 minLasts 2 – 4 hoursAfter-effects 2 – 8 hours

Also recorded: Insufflated · Intravenous · Intramuscular. See full page: psychedex.org/substances/ketamine

Body and dependence

Acute toxicity
Low
Chronic toxicity
High
Physical dependence
Moderate
Psychological dependence
High
Withdrawal
Moderate
Compulsive redosing
High

Tolerance

Builds
Moderate
Fully resets after
4 weeks
Carries over to
phencyclidine; methoxetamine; deschloroketamine; 2-fluorodeschloroketamine; nitrous oxide

Effectslikely at a common dose

Perception
Touch suppression; Spatial disorientation; Depth perception distortion; +18 possible, including Vestibular distortion, Visual acuity suppression, Visual haze / noise
Body
Pain suppression; Motor control impairment; +27 possible, including Nystagmus (eye wobbles), Dizziness, Vasoconstriction
Thinking
Focus suppression; Cognitive impairment; Thought disorganization; Memory suppression; +21 possible, including Confusion, Analysis suppression, Decision impairment
Feeling
none likely · 7 possible, including Empathy suppression, Anxiety, Emotional lability
Self
Depersonalization; Derealization; +5 possible, including Communication suppression, Social disconnection, Craving
Time
Time alteration; +3 possible, including Temporal disorientation
Awareness
none likely · 2 possible

Who shouldn't take it

Absolute
Uncontrolled hypertension; Severe cardiovascular disease; Concurrent opioid or CNS depressant use; Psychotic disorders; Pregnancy
Relative
Hepatic impairment; Pre-existing urinary tract disease; Thyrotoxicosis

Combinations79 recorded

Lethal (23)
Acetylfentanyl; Benzodiazepines, Barbiturates; Buprenorphine; Codeine; Dihydrocodeine; Ethylmorphine; Fentanyl; GHB, Baclofen; GHB, GBL; Heroin; Hydrocodone; Hydromorphone; Kratom; Local anesthetics; Methadone; Morphine; O-Desmethyltramadol; Oxycodone; Oxymorphone; Sufentanil; Tapentadol; Tramadol; U-47700
Dangerous (35)
Alpha-2 adrenergic receptor antagonist; Amphetamines; Benzodiazepines; Buprenorphine, Kratom; Cannabis, THC; Clonidine, Guanfacine; Gabapentin, Pregabalin; MDMA, Amphetamines; Naltrexone; NRIs; NSAIDs; Stimulants; THC; Anticholinergics; Antihistamines; Atypical antipsychotics; Buspirone; Caffeine; CBD; Dopamine agonists; DXM; Glutamate modulator; Huperzine A; Ibogaine; and 11 more, see full page
Caution (17)
See full page: psychedex.org/substances/ketamine
Not graded (4)
Not listed never means safe.

Seek help immediately if

  • Severe disorientation; unable to move or speak (deep dissociation / "k-hole")
  • Complete loss of coordination — cannot stand or walk safely
  • Vomiting while incapacitated (choking / aspiration risk)
  • Very high blood pressure; fast heart rate
  • Slow or shallow breathing at high doses (especially mixed with depressants)
  • Unconsciousness; rarely, seizures

What to do

  1. Move them somewhere safe, away from stairs, water, roads, and sharp edges — they cannot protect themselves
  2. Place in the recovery position if vomiting or unconscious (aspiration is a key risk)
  3. Stay with them and reassure calmly; keep the environment quiet
  4. If breathing is slow/shallow or they are unresponsive, call emergency services
  5. Do not let them wander; do not leave them alone
  6. Be ready to give rescue breaths / CPR

Effects wear off with time in a safe, monitored setting. The main dangers are physical injury and aspiration while incapacitated, and respiratory depression when combined with other depressants — not the dissociation itself.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

psychedex.org/substances/ketamine · Version r1 · Not medical adviceValues as of
On the printout