RESEARCH MONOGRAPH · KDC-MN-170

Ketamine

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 2 min read

Our opinion on this compound

82/100

The mechanism story that rewrote psychiatry, and an open question about how the field used it

Ketamine is the molecule that broke the monoamine hypothesis. For 50 years antidepressants were all about serotonin and norepinephrine, then a single subanesthetic IV ketamine dose produced sustained antidepressant effect within hours, validated by Yale and Mt Sinai groups in the 2000s, and the field had to rebuild its theory of depression around glutamate, AMPA receptor trafficking, BDNF, and synaptic plasticity.

Mechanism is well-mapped at this point. Non-competitive NMDA receptor antagonism is the primary action, with the proposed antidepressant mechanism going through GABAergic interneuron inhibition, a glutamate surge, AMPA receptor activation, BDNF release, mTORC1 signaling, and synaptic protein synthesis. The hydroxynorketamine metabolite (especially the (2R,6R) form) may contribute independently of NMDA, and there's ongoing debate about how much the dissociative experience itself contributes versus the molecular cascade.

Clinical evidence at this point is dense. Multiple meta-analyses of subanesthetic IV ketamine in treatment-resistant depression show response rates in the 50-70% range with effect sizes that exceed most conventional antidepressants. The catch is that effects last days to weeks, not months, which is why repeat dosing protocols evolved.

The enantiomer story matters. Racemic ketamine is a 50:50 mix of S- and R-ketamine. Esketamine (the S-enantiomer, see separate entry) got FDA approval as Spravato in 2019 via intranasal delivery. Arketamine (R-enantiomer, see separate entry) has emerging data suggesting it may produce antidepressant effects without the dissociative profile, which is interesting if it replicates.

Sourcing for research: ketamine HCl is a controlled substance in most jurisdictions, scheduled under various national frameworks. Pharmacopoeia-grade material exists. Analytical characterization is straightforward, HPLC verification is standard.

Safety profile depends heavily on dose and context. Subanesthetic IV doses in controlled medical settings have an excellent safety record. Recreational/escalated dosing causes urinary tract toxicity (ketamine bladder syndrome) that's well-documented at chronic high exposures.

What we like: this is one of the most important molecular discoveries in modern CNS pharmacology, and it opened up an entire glutamate-based therapeutic class that includes esketamine, AXS-05, and the rapid-acting antidepressant pipeline. What we dont like: the clinic-scaling has run ahead of the long-term safety data in some places, and the dose-escalation patterns that emerge with home/at-scale use are a real research concern.

Evidence: 92
Mechanism: 85
Reliability: 82
Safety: 65
Sourcing: 78
Value: 70
Signal: 92
Staying power: 92

Plain-language summary Intrigue 90 / 100

Ketamine is an NMDA receptor antagonist developed in the 1960s as an anesthetic. The dissociative anesthesia profile and rapid antidepressant effects (at sub-anesthetic doses) have made it one of the most consequential psychiatric breakthroughs in decades. Schedule III in the US. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

NMDA receptor antagonist / dissociative anesthetic

A non-competitive NMDA receptor antagonist FDA-approved as a dissociative anesthetic since 1970, with rapid antidepressant activity at sub-anesthetic doses.

Abstract

Ketamine (CAS 6740-88-1; molecular formula C13H16ClNO; molecular weight 237.73) is a non-competitive NMDA receptor antagonist developed in 1962 by Calvin Stevens at Parke-Davis and approved by the FDA in 1970 as a dissociative anesthetic. The compound is used clinically for anesthesia, procedural sedation, and analgesia. Sub-anesthetic doses (0.5 mg/kg IV or equivalent) produce rapid antidepressant effects in treatment-resistant depression, an indication for which the (S)-enantiomer (esketamine) is FDA-approved as Spravato. Mechanism includes NMDA receptor blockade, AMPA receptor potentiation through downstream signaling, and modest opioid receptor effects. Schedule III in the United States.

Mechanism of action

Non-competitive NMDA receptor antagonist; rapid antidepressant effects through downstream AMPA potentiation and BDNF release.

Reported research dose ranges

Reported research dose ranges in the literature.

References

Berman RM, et al. Antidepressant effects of ketamine in depressed patients. Biol Psychiatry 2000.

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KDC-MN-170

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

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Ketamine

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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