RESEARCH MONOGRAPH · KDC-MN-039

Dimiracetam

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

Our opinion on this compound

49/100

Failed neuropathic pain candidate with an unusual mechanism, still occasionally interesting

Dimiracetam is one of the more chemically distinct compounds on this list. The bicyclic dione scaffold puts it structurally far from the standard racetam core, and Spinal Pharmaceuticals (now Naurex) developed it specifically for chemotherapy-induced neuropathic pain rather than the cognitive enhancement angle that drove most of the racetam programs.

The mechanism work is where it gets interesting. Rather than the SV2A or AMPA modulation story, dimiracetam appears to act primarily at the level of D-serine release and NMDA glycine site modulation, possibly through glial mechanisms that arent fully worked out. The Caprioli and Naurex papers describe it as a use-dependent NMDA modulator, which is a different category of activity than anything else in the racetam family.

What we like: novel mechanism within a familiar scaffold, real preclinical evidence in oxaliplatin and paclitaxel-induced neuropathy models, and a phase 2 trial that actually got run (DIMI-201) for chemotherapy-induced peripheral neuropathy. The drug failed primary endpoints but the trial design was reasonable and the safety data was solid.

What we dont like: the clinical failure was decisive enough that development effectively stopped after the phase 2 readout, the mechanism story still has gaps, and there's not a lot of independent verification of the D-serine release hypothesis outside of the original group's work.

For research, dimiracetam is interesting if you're working in neuropathic pain models or want a tool compound for use-dependent NMDA modulation. The behavioral profile is unusual, it doesnt produce much of the classical NMDA-antagonist signature (no ataxia, minimal sedation), which suggests the mechanism is genuinely distinct from straight channel block.

Sourcing is okay but not great. The molecule is patented, production scale outside of clinical programs has been limited, and reference standards arent always easy to source. HPLC and at least one orthogonal method (probably NMR for this scaffold) are worth running.

Honestly, this is a compound where the failed phase 2 left an interesting mechanistic story hanging. Worth keeping in the racetam shelf as a curiosity, but dont expect it to deliver in standard cognitive paradigms.

Evidence: 45
Mechanism: 55
Reliability: 50
Safety: 65
Sourcing: 50
Value: 45
Signal: 40
Staying power: 40

Plain-language summary Intrigue 28 / 100

Dimiracetam is a bicyclic dione racetam analog. Limited published research; used in academic settings to study racetam structure-activity relationships. 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.

Bicyclic dione racetam analog

A bicyclic 2,5-pyrrolidinedione developed by Sigma-Tau for chemotherapy-induced peripheral neuropathy.

Abstract

Dimiracetam (1,4-diazabicyclo[3.3.0]octane-2,5-dione; CAS 126716-03-2; molecular formula C7H10N2O2; molecular weight 154.17) is a bicyclic 2,5-pyrrolidinedione developed by Sigma-Tau (now Defiante Farmaceutica) in Italy with development focused on chemotherapy-induced peripheral neuropathy. The compound is structurally distinct from open-chain racetams in featuring a fused bicyclic scaffold with two carbonyls per ring. Mechanism is incompletely characterized but appears to involve modulation of glutamatergic transmission with NMDA-related effects, distinct from the AMPA potentiation typical of racetams. Phase 2 trials in chemotherapy-induced peripheral neuropathy showed modest reduction in neuropathic pain measures; the program advanced toward Phase 3 but encountered commercial and design challenges. The compound is not approved by any regulatory authority. Limited research-grade availability. Pharmacokinetics: short half-life (1 to 2 hours) and high oral bioavailability. Reported research dose ranges in the literature span 200 to 1600 mg (Phase 2 trials).

Mechanism of action

Glutamatergic modulation with NMDA-related effects; distinct from typical racetam AMPA pharmacology.

Reported research dose ranges

200 to 1600 mg, as reported research dose ranges in the literature (Phase 2 trials).

References

Sigma-Tau development program for dimiracetam; Phase 2 chemotherapy-induced peripheral neuropathy results.

Read the full monograph

The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, reported research dose ranges, sourcing and quality verification, reconstitution and handling, stack interaction considerations, and a curated reference list. Available as a research-use-only PDF download.

KDC-MN-039

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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Dimiracetam

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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