Dissociatives
Ketamine
An FDA-approved anesthetic, a breakthrough antidepressant, a widely used recreational drug, and a genuinely unique pharmacological tool. Ketamine is the only substance on this page that's simultaneously available by prescription, used in emergency rooms, administered in therapy clinics, and sold on the street.
The Basics
Dose defines the experience completely
At low doses, ketamine produces mild dissociation, mood lift, pain relief, and a pleasant floaty feeling. At moderate doses, visual distortions, time dilation, and a sense of detachment from your body emerge. At high doses — the "K-hole" — you experience complete dissociation from your body and environment, entering a deeply internal, often surreal and visionary state that some compare to a near-death experience.
Therapeutically, ketamine is showing extraordinary results for treatment-resistant depression. A single infusion can produce antidepressant effects within hours — compared to weeks for SSRIs. Esketamine (Spravato), the S-isomer nasal spray, is FDA-approved for treatment-resistant depression. The mechanism appears to involve NMDA antagonism triggering rapid neuroplasticity through BDNF and mTOR pathways.
The Science
NMDA antagonism and rapid antidepressant action
NMDA receptor blockade
Ketamine blocks NMDA glutamate receptors — the same mechanism as PCP and nitrous oxide but with a much more favorable safety profile. This disrupts normal sensory processing and produces the characteristic dissociative state.
Rapid neuroplasticity
NMDA blockade triggers a cascade: increased BDNF, activation of mTOR signaling, synaptogenesis (new synaptic connections) within hours. This is the proposed mechanism for rapid antidepressant effects — the brain literally rewires faster under ketamine.
S vs R isomers
Racemic ketamine (standard) contains both S and R isomers. Esketamine (S-isomer, Spravato) is ~3–4x more potent at the NMDA receptor. Arketamine (R-isomer) may have stronger antidepressant effects with less dissociation — research is ongoing.
Opioid system involvement
Emerging research suggests ketamine's antidepressant effects may partially involve opioid receptor activation. This is scientifically interesting and clinically relevant — it raises questions about abuse potential in therapeutic contexts.
Dosing Guide
Insufflated (intranasal) — the most common recreational route
Clinical/therapeutic dosing (IV infusion, typically 0.5mg/kg over 40 minutes) is completely different from recreational dosing. The numbers below are for insufflated powder — the most common non-clinical route.
Low / Social
15–30mg
Mild dissociation, mood lift, slight floatiness, pain relief. Functional. Comparable to a couple of drinks in terms of impairment level but a completely different subjective quality.
Moderate
30–75mg
Clear dissociation. Body feels distant, visual field distorts, time perception shifts. Music becomes immersive. Walking may become uncoordinated. The core recreational range for most users.
Strong
75–150mg
Approaching or entering the K-hole. Profound dissociation from body and environment. Internal visionary experiences. Motor control significantly impaired. Lie down in a safe space.
K-hole
150mg+
Complete dissociation. You are no longer meaningfully in your body or aware of your environment. Deeply internal experience — surreal, sometimes terrifying, sometimes profoundly meaningful. A sitter is essential. You will not be able to help yourself.
⚠ Tolerance builds fast
Ketamine tolerance develops rapidly with regular use, and the dose escalation required to achieve the same effects increases bladder and urological damage risk disproportionately. Frequent use (more than once a week) significantly accelerates harm. Many people who develop problematic ketamine use describe a pattern where recreational doses stopped working and escalation felt inevitable.
Harm Reduction
The bladder is the long-term risk
Ketamine cystitis is the most serious long-term risk. Chronic use damages the bladder lining — causing frequency, urgency, pain, and in severe cases, a bladder so damaged it requires surgical removal. This is not theoretical. It happens to recreational users who use frequently. Any urinary symptoms during a period of ketamine use should be taken seriously and use should stop.
Do not combine with depressants. Ketamine + alcohol, opioids, or benzodiazepines increases risk of respiratory depression and vomiting while unconscious (aspiration). Ketamine alone has a wide safety margin. Ketamine + other depressants narrows it significantly.
Vomiting while dissociated is a real aspiration risk. If you or someone is K-holing and vomits, recovery position immediately. This is the acute physical danger scenario with ketamine.
Frequency matters more than dose. Once a month is dramatically different from twice a week in terms of bladder health, tolerance, and psychological dependence. If you use ketamine, spacing is the single most important variable.
Psychological dependence is real. Ketamine can become compulsive — the dissociative escape from emotional pain is reinforcing for people who are in pain. If you notice you're using ketamine to avoid feeling things, that's a signal worth paying attention to.
Reagent test your material. Street ketamine can contain adulterants. Mandelin reagent: ketamine turns orange. Mecke: no reaction (useful for ruling out other substances).
Tim's Take
Ketamine is the substance on this site with the weirdest gap between how it's being marketed and what it actually is.
Pharmacologically, ketamine is a dissociative anesthetic that, in sub-anesthetic doses, produces rapid antidepressant effects. That's real. The clinical evidence for ketamine in treatment-resistant depression is some of the strongest evidence for any psychiatric intervention in the past two decades. Spravato (esketamine) is FDA approved. IV ketamine protocols have moved from fringe to mainstream at an unusual speed.
A lot of what's being sold right now as "ketamine therapy" is just ketamine. No therapist in the room. No integration. No preparation. A clinic, a chair, an IV drip or a lozenge, and you go home two hours later. That's not therapy. That's a ketamine nap. The evidence base for ketamine as an antidepressant is built on protocols that integrate psychotherapy into the experience. The evidence base for a ketamine drip by itself is much thinner and a lot of what's getting billed for is essentially off-label infusions without the wraparound care.
The second thing worth knowing is the bladder. Ketamine at high frequency or high dose causes ulcerative cystitis. This is well documented in recreational heavy users and it's dose and frequency dependent. A monthly therapeutic session is almost certainly fine. Daily recreational use is on a timeline toward significant urological damage. The clinical signs show up before the permanent damage does, so if you're using ketamine regularly and you're noticing urinary urgency or pain, the substance is telling you to stop.
Ketamine has more therapeutic promise than most substances on this site. It also has a pattern of abuse that's easy to slide into because the experience is short, the comedown is mild, and tolerance builds fast enough that weekly use becomes daily use becomes multiple times daily. Respect the dose. Respect the frequency. Don't let a clinic sell you a drip as a substitute for actually doing the work.
If you or someone you know needs support
The Fireside Project provides free emotional support during or after a psychedelic or dissociative experience. Available by call or text, 24 hours a day.
Call or text · Available 24/7 · Free · Non-judgmental
Know Before You Go
Based on documented risks and harm reduction literature, practitioners typically advise the following.
Bladder damage from chronic use is the primary long-term risk. Any urinary symptoms = stop using immediately.
Do not combine with alcohol, opioids, or benzos. Respiratory depression and aspiration risk.
Frequency matters more than dose. Once a month vs twice a week = completely different risk profiles.
K-hole = complete dissociation. Lie down, have a sitter, recovery position if vomiting.
Tolerance builds rapidly. Dose escalation accelerates bladder damage disproportionately.
Fireside Project: 623-473-7433. Save it before you need it.
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