Dissociative · arylcyclohexylamine
Ketamine
aka K · Ket · Kit Kat · Special K · Vitamin K
Last verified
Ketamine is an NMDA receptor antagonist originally developed as a dissociative anesthetic. At sub-anesthetic doses it produces euphoria, body dissociation, sensory distortion and (at higher doses) the so-called "k-hole" — a deep dissociated state that can feel like leaving one's body or being in another reality entirely. It is also being studied and used clinically as a rapid-onset antidepressant.
Chronic, heavy use of ketamine is associated with serious, sometimes irreversible bladder damage (ketamine-induced cystitis) and cognitive impairment. The dose-response relationship is steep; what feels like 1.5× a normal dose can land in a k-hole; and tolerance builds within days, encouraging escalating use.
Harm reduction
- Weigh your doses. Eyeballing ketamine is unreliable; a small kitchen scale (0.01 g precision) is the right tool. Pre-measured bumps in a small container help avoid creeping doses.
- Wait 60 minutes between bumps. The temptation to chase the come-up is the single largest driver of unintended k-holes.
- Never combine with depressants. GHB/GBL, opioids, alcohol and benzodiazepines all cause respiratory depression. Ketamine combined with any of them sharply increases the risk of unconsciousness, vomiting and aspiration.
- K-hole posture matters. If you go deeper than intended, you may be unable to move. Lie on your side in a safe place. Never k-hole alone in a chair or near hard edges.
- Watch your bladder. If urination becomes painful, frequent, urgent or bloody, stop using completely. Bladder symptoms can persist or progress after stopping; see a urologist early.
- Frequency matters more than dose. Multiple sessions per week (or daily use) is where the worst harms cluster. Most users tolerate occasional ketamine well for years; daily users routinely develop serious problems within months.
Dosage.
Insufflated
- Threshold
- 10 mg
- Light
- 20–50 mg
- Common
- 50–100 mg
- Strong
- 100–150 mg
- Heavy
- 150 mg
Oral
- Threshold
- 40 mg
- Light
- 75–150 mg
- Common
- 150–300 mg
- Strong
- 300–450 mg
- Heavy
- 450 mg
Intramuscular
- Threshold
- 10 mg
- Light
- 15–40 mg
- Common
- 40–75 mg
- Strong
- 75–125 mg
- Heavy
- 125 mg
| Route | Threshold | Light | Common | Strong | Heavy |
|---|---|---|---|---|---|
| Insufflated | 10 mg | 20–50 mg | 50–100 mg | 100–150 mg | 150 mg |
| Oral | 40 mg | 75–150 mg | 150–300 mg | 300–450 mg | 450 mg |
| Intramuscular | 10 mg | 15–40 mg | 40–75 mg | 75–125 mg | 125 mg |
Start at the bottom. Body chemistry, tolerance, and combinations all matter.
Duration.
Insufflated
total ~ 340 min- Onset
- 5–10 min
- Peak
- 30–45 min
- Offset
- 30–45 min
- After
- 60–240 min
Oral
total ~ 600 min- Onset
- 10–30 min
- Peak
- 45–90 min
- Offset
- 60–120 min
- After
- 2–6h
Intramuscular
total ~ 245 min- Onset
- 1–5 min
- Peak
- 20–30 min
- Offset
- 20–30 min
- After
- 60–180 min
Effects.
Positive
- Euphoria
- Dissociation from body
- Music and sound enhancement
- Reduction of physical pain
- Anti-depressant effects (low doses, infrequent use)
Neutral
- Time distortion
- Visual changes (motion blur, depth flattening)
- Nystagmus (involuntary eye movement)
- Slurred speech
Negative
- Severe ataxia (loss of motor coordination) at high doses
- Nausea, especially when combined with food or alcohol
- K-hole (intense ego dissolution / out-of-body experience; sought by some, terrifying for others)
- Bladder damage with chronic frequent use (a serious risk)
- Memory impairment short-term, and possibly long-term with heavy use
Interactions.
Heads up
Many drug combinations are unsafe even at low doses. When in doubt, take less or abstain. Always cross-check with the interaction checker tool.
Dangerous
Combination may cause serious harm. Avoid.
- tramadol
- ghb
- opioids
- alcohol
Unsafe
Substantial risk. Combination not recommended.
- dxm
- benzodiazepines
- gbl
Caution
Mild interaction. Use with reduced doses.
- stimulants
- mdma
- cannabis
- psychedelics
Testing.
- ReagentMorrisExpected reactionYellow to orange (after 30 seconds)
- ReagentMeckeExpected reactionNo reaction (negative expected)
- ReagentMandelinExpected reactionOrange-brown
- ReagentSimonExpected reactionNo reaction
| Reagent | Expected reaction |
|---|---|
| Morris | Yellow to orange (after 30 seconds) |
| Mecke | No reaction (negative expected) |
| Mandelin | Orange-brown |
| Simon | No reaction |
Cross-check with a secondary reagent. Tests tell you what something isn't, not always what it is.
Legal status.
- DEGermanyPrescription only
- ATAustriaPrescription only
- CHSwitzerlandIllegal
- NLNetherlandsSchedule I
- BEBelgiumSchedule I
- LULuxembourgPrescription only
- FRFranceIllegal
- ESSpainIllegal
- PTPortugalPrescription only
- ITItalyPrescription only
- PLPolandPrescription only
- CZCzechiaPrescription only
- SESwedenPrescription only
- DKDenmarkPrescription only
- NONorwayPrescription only
- FIFinlandPrescription only
- IEIrelandClass B
- UKUnited KingdomClass B
- USUnited StatesSchedule III
- CACanadaSchedule I
- AUAustraliaSchedule 8
- TRTurkeyPrescription only
| Country | Status |
|---|---|
| DEGermany | Prescription only |
| ATAustria | Prescription only |
| CHSwitzerland | Illegal |
| NLNetherlands | Schedule I |
| BEBelgium | Schedule I |
| LULuxembourg | Prescription only |
| FRFrance | Illegal |
| ESSpain | Illegal |
| PTPortugal | Prescription only |
| ITItaly | Prescription only |
| PLPoland | Prescription only |
| CZCzechia | Prescription only |
| SESweden | Prescription only |
| DKDenmark | Prescription only |
| NONorway | Prescription only |
| FIFinland | Prescription only |
| IEIreland | Class B |
| UKUnited Kingdom | Class B |
| USUnited States | Schedule III |
| CACanada | Schedule I |
| AUAustralia | Schedule 8 |
| TRTurkey | Prescription only |
Information, not legal advice. Status varies by region and changes over time.
FAQ.
How long does Ketamine last?
A typical oral Ketamine experience peaks around 45–90 minutes and then tails off, with after-effects that can run several hours. The exact window depends on dose, body weight and what else you've eaten or taken.
Can you overdose on Ketamine?
Yes. Higher doses sharply raise the risk of acute harm (cardiovascular strain, hyperthermia, serotonin issues for serotonergic drugs, respiratory depression for downers). Stick to the lowest dose that gives you the effect you're after, never re-dose blindly, and use our [dose calculator](/tools/dosage-calculator) before you weigh anything out.
Is Ketamine addictive?
Ketamine can produce psychological dependence with frequent use, especially in unstable settings or when used to self-medicate. Physical dependence varies by substance class; the safest pattern is occasional use with long breaks (often 4–6 weeks minimum) and an honest read on why you're reaching for it.
What does Ketamine feel like?
Common subjective effects include the ones listed in the Effects section above. Set and setting massively shape the experience: a calm space, trusted people, food eaten, sleep the night before, and your own current mood all matter more than most people expect.
Can you mix Ketamine with alcohol?
Mixing with alcohol is rarely a good idea — it dulls your judgement of how much you've taken, dehydrates you, and stacks cardiovascular load. If alcohol is on the table, drink less than normal, alternate with water, and run the combination through our [interaction checker](/tools/interaction-checker) first.
How do I test Ketamine at home?
A basic reagent kit (Marquis + Mandelin + Mecke for most stimulants/entactogens; Ehrlich for tryptamines) gives you a fast presence check. It does NOT measure dose or purity, but it does rule out the most dangerous misrepresentations. See the [reagent guide](/tools/reagent-guide) for expected colors per reagent.
How much Ketamine is too much?
There's no single number that applies to everyone. As a rule, anything above the 'strong' dose range (300-450 mg for the primary route) carries sharply higher risk of acute harm. Start low, don't redose blindly, and remember that purity varies batch to batch.
How long until Ketamine kicks in?
Onset is typically 10-30 minutes via the primary route. Don't redose because you 'don't feel anything yet.' Many people have overdone it by stacking doses during the come-up window.
Can you build tolerance to Ketamine?
Yes. Regular use builds tolerance, meaning you need more for the same effect. This escalation increases both health risk and dependence potential. The best counter is long breaks between sessions (2-4 weeks minimum for most substances, 3 months for MDMA-class drugs).
Is Ketamine tested for in standard drug screens?
Standard 5-panel workplace tests (SAMHSA-5) do not specifically screen for Ketamine. Extended panels (10-12 panel) or specialized tests may detect it. If testing is a concern, research the specific panel being used.