Overview
What is Ketamine?
Common and street names
ket · K · special K
Drug category
Dissociative
Forms and appearance
Non-medical ketamine is commonly encountered as white crystals or powder. Other powders may look identical.
How it is commonly used
Non-medical ketamine is commonly snorted. Other routes occur and can change onset, intensity and risk; this guide does not provide dosing instructions.
Brain & body
How Ketamine affects signalling and behaviour
Ketamine primarily blocks NMDA-type glutamate receptors, changing communication across sensory, memory and cortical networks. Its effects are not the same as classical serotonergic psychedelics.
Explore reward, cues, craving, stress, tolerance and neuroplasticity without a simplistic “hijacked brain” model.
Effects & risks
What people may experience — and what can go wrong
Commonly reported effects
- Dissociation and altered perception
- Reduced pain perception
- Impaired balance and coordination
- Changes in time, body and spatial perception
Short-term risks
- Falls, accidents and vulnerability
- Vomiting or aspiration when heavily sedated
- Panic, confusion or severe dissociation
- Greater sedation when mixed with depressants
Longer-term risks
- Bladder and urinary-tract damage
- Dependence and escalating use
- Cognitive or memory problems
- Abdominal pain and other physical complications with heavy repeated use
Mental-health effects
Ketamine can produce anxiety, confusion and unusual perceptual experiences. Frequent high-intensity use may worsen cognitive and mental-health difficulties for some people; clinical ketamine treatment is not equivalent to uncontrolled non-medical use.
Dependence, tolerance & withdrawal
Repeated use can change the pattern
Psychological dependence and compulsive use can become substantial. Tolerance may encourage escalation. People using frequently who develop urinary symptoms should seek medical assessment early rather than waiting for severe pain.
Mixing drugs
Interaction risks to know
Ketamine + alcohol can increase sedation, vomiting and injury risk.
Ketamine + opioids or benzodiazepines can add to sedation and respiratory risk.
Unverified powders can contain different or additional substances.
The absence of a recorded interaction does not mean that a combination is safe. Strength, dose, health, tolerance, contamination and other substances can alter risk.
Check another combinationHarm reduction
Practical ways to reduce risk
Avoid mixing with alcohol, opioids, benzodiazepines or other sedatives.
Do not use alone where loss of coordination or consciousness could go unnoticed.
Seek medical advice promptly for urinary frequency, pain, blood in urine or persistent abdominal pain.
Do not assume a white powder is ketamine from appearance.
Harm reduction can reduce some risks; it cannot make an unregulated drug, dose or combination risk-free.
Emergency
When to call 999
- Cannot be woken or abnormal breathing
- Seizure
- Severe confusion, agitation or injury
- Persistent vomiting with reduced consciousness
Treatment & support
Help does not require one fixed recovery goal
UK drug and alcohol services can assess physical health, mental health, dependence, risk, housing and support needs, then agree a plan with the person. Goals may include immediate harm reduction, stabilisation, reduction or stopping use.
Psychological dependence and compulsive use can become substantial. Tolerance may encourage escalation. People using frequently who develop urinary symptoms should seek medical assessment early rather than waiting for severe pain.
Brief history
How we got here
Ketamine was developed in the 1960s as a dissociative anaesthetic and entered medical use soon afterwards. Recreational use expanded later, while modern research and clinical practice have also explored carefully controlled ketamine-related treatments for some mental-health conditions.
Read the history guideKey facts & misconceptions
Three useful corrections
Ketamine's medical use does not make non-medical supply predictable.
A 'K-hole' is profound intoxication, not a reliable dose target.
Appearance cannot distinguish ketamine from other powders.
Frequently asked questions
Quick answers
What type of drug is Ketamine?
Ketamine is described here as dissociative. Some drugs cross categories, and mixtures may contain more than one drug type.
Can Ketamine be identified by appearance?
No. Appearance, packaging, a logo or colour cannot reliably establish identity, strength or contamination.
When should I call 999?
Call 999 for a suspected drug emergency, including reduced consciousness, abnormal breathing, seizure, severe chest pain or severe confusion. Cannot be woken or abnormal breathing
Evidence & governance
Sources and review
Responsible organisation: TD Consultancy
Published: 5 August 2026 · Last reviewed: 5 August 2026
Next formal review: February 2027, or earlier if material safety or legal information changes.
Evidence on illicit drug composition and emerging markets can change quickly. Legal status can be compound- and preparation-specific. Links below are prioritised to current official UK guidance.