Nefiracetam

Nefiracetam at a Glance

Nefiracetam is a synthetic pyrrolidone (“racetam”) developed in Japan as an investigational cognition-and-mood drug — not as a dietary supplement. Structurally it is piracetam’s scaffold carrying a 2,6-dimethylphenyl group, and it was known in development as DM-9384.

It has no dietary source and no deficiency state to correct; every effect is an extra laid on a normal system.

What makes it unusual is the gap between mechanism and evidence. Nefiracetam’s molecular actions are unusually well mapped — it potentiates NMDA and nicotinic acetylcholine receptors at low nanomolar concentrations through PKC and CaM-kinase signalling — and that deep preclinical literature is exactly what gets quoted in marketing. The human record is far thinner: three double-blind trials, all in stroke patients, with mixed-to-null results, and one Phase 2 Alzheimer’s trial that completed in 2002 and never published a positive result.

The honest bottom line: it was never approved as a medicine anywhere, the one positive human signal is a subgroup at the top dose, and repeat-dose animal toxicology turned up testicular atrophy in two species. For a compound sold online to young men, that last fact is the most decision-relevant thing on the page.

What It’s Used For

Ranked by how well the evidence actually holds up:

Post-stroke apathy — the best human evidence, and genuinely mixed: one positive double-blind trial at 900 mg/day, one null confirmatory trial that was far too small to settle it.
Post-stroke depression — a well-conducted trial that was null overall; only the most severely depressed quintile showed anything.
Cognitive enhancement and dementia — the marketed use, with no published human trial supporting it.
Neuropathic pain and seizures — rodent models only.

Be sceptical of the memory-enhancement claim that drives online sales. There is no published human trial showing cognitive benefit in healthy people, and the completed Alzheimer’s Phase 2 has no positive result on record. The mechanistic literature is genuinely impressive, but a well-characterised mechanism is not evidence of a benefit — and here the two point in noticeably different directions.

How It Works

Nefiracetam’s mechanism is the strongest part of its file. At low nanomolar concentrations it potentiates NMDA receptor currents by activating protein kinase C, which reduces the voltage-dependent magnesium block that normally gates the receptor ^{8Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →}. In parallel it enhances and prolongs acetylcholine-evoked currents at nicotinic receptors ^{8Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →}. Downstream, it activates CaMKII and related calcium/calmodulin kinases feeding into CREB — the signalling cascade that underwrites long-term potentiation and memory consolidation ^{9,10Reference 9Moriguchi S et al. · 2009AnimalNefiracetam activation of CaM kinase II and protein kinase C mediated by NMDA and metabotropic glutamate receptors in olfactory bulbectomized miceView study →Reference 10Han F et al. · 2009AnimalImprovement of depressive behaviors by nefiracetam is associated with activation of CaM kinases in olfactory bulbectomized miceView study →}.

The PKC activation follows a bell-shaped dose–response, peaking around 10 nM. That is worth noting because it implies more is not better, and it is a plausible reason the 900 mg and 600 mg arms in the clinical trials behaved so differently.

One correction to a claim that circulates: nefiracetam is sometimes described loosely as “a GABA compound.” Its GABAergic effects are real but secondary — the primary actions are glutamatergic and cholinergic. Describing it as a GABA drug gets the pharmacology backwards.

Pharmacology & Research

Nefiracetam is a synthetic pyrrolidone (“racetam”) nootropic — chemically N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide (CAS 77191-36-7) — developed in Japan as an investigational cognition-and-mood drug rather than a dietary supplement. Its molecular actions are unusually well mapped: at low nanomolar concentrations it potentiates NMDA and nicotinic acetylcholine receptor currents through protein kinase C and CaM-kinase signalling ^{8,9Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →Reference 9Moriguchi S et al. · 2009AnimalNefiracetam activation of CaM kinase II and protein kinase C mediated by NMDA and metabotropic glutamate receptors in olfactory bulbectomized miceView study →}.

The clinical reality is much thinner than the mechanism suggests. The only reasonable-sized human trials tested post-stroke apathy and depression, where results were inconsistent and depended on dose and on co-existing depression ^{1,2,3Reference 1Robinson RG et al. · 2009RCTDouble-blind treatment of apathy in patients with poststroke depression using nefiracetam — randomised controlled trialView study →Reference 2Starkstein SE et al. · 2016RCTA randomized, placebo-controlled, double-blind efficacy study of nefiracetam to treat poststroke apathy — randomised controlled trialView study →Reference 3Robinson RG et al. · 2008RCTDouble-blind randomized treatment of poststroke depression using nefiracetam — randomised controlled trialView study →}, and no published trial supports the “memory enhancement in healthy people” claim that drives online sales. Because it is a drug (never approved) and not a nutrient, there is no dietary source, no RDA, and no established over-the-counter dose — and its development was shadowed by dose-dependent organ toxicity in animals.

Best-supported:the strongest human signal is for post-stroke apathy in patients who also have depression, where 900 mg/day beat 600 mg/day and placebo in one double-blind trial ^{1Reference 1Robinson RG et al. · 2009RCTDouble-blind treatment of apathy in patients with poststroke depression using nefiracetam — randomised controlled trialView study →}; even this is modest and inconsistently replicated.

Emerging / cautiously endorsed:deep and well-replicated preclinical work on NMDA/nicotinic potentiation and CaMKII/CREB signalling makes it a genuine research tool for synaptic disorders (e.g. reversing MECP2-knockout neuronal pathology in Rett-syndrome models) ^{8,9,11Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →Reference 9Moriguchi S et al. · 2009AnimalNefiracetam activation of CaM kinase II and protein kinase C mediated by NMDA and metabotropic glutamate receptors in olfactory bulbectomized miceView study →Reference 11Trujillo CA et al. · 2021Pharmacological reversal of synaptic and network pathology in human MECP2-KO neurons and cortical organoidsView study →} — mechanism, not proven benefit.

Popular but thin / overhyped:“nootropic” memory enhancement in healthy users. A completed Phase 2 Alzheimer’s trial (NCT00001933) never reported positive published results, and the cognition data are otherwise animal-only ^{4Reference 4National Institute of Mental Health · 2002Clinical trialNefiracetam therapy of Alzheimer’s type dementia (Phase 2, completed 2002) — clinical trial recordView study →}.

The honest miss / caveat:a later, properly controlled trial of nefiracetam for post-stroke apathy without depression found no benefit over placebo ^{2Reference 2Starkstein SE et al. · 2016RCTA randomized, placebo-controlled, double-blind efficacy study of nefiracetam to treat poststroke apathy — randomised controlled trialView study →}, and its overall post-stroke depression trial was null except in the most severely depressed subgroup ^{3Reference 3Robinson RG et al. · 2008RCTDouble-blind randomized treatment of poststroke depression using nefiracetam — randomised controlled trialView study →}. Add the animal testicular and renal toxicity signals and the risk-benefit case for casual use is poor ^{14,15,16Reference 14Shimomura K et al. · 2004Testicular toxicity induced in dogs by nefiracetam, a neurotransmission enhancerView study →Reference 15Shimada M et al. · 2003AnimalInvestigation of testicular toxicity of nefiracetam, a neurotransmission enhancer, in ratsView study →Reference 16Tsuchiya Y et al. · 2003Comprehensive evaluation of canine renal papillary necrosis induced by nefiracetam, a neurotransmission enhancerView study →}.

Evidence by IndicationStrength of support · Beta

Support is an experimental score I’m building — a composite weighted by study type (human > animal > in vitro > review) and study volume. It’s a beta: a fast way to rank strength of evidence at a glance, not a validated metric. Each application links down to its write-up.

Mechanisms

Target / pathway	Effect	Relevant to
NMDA receptor (glycine site)	Potentiates currents; reduces voltage-dependent Mg²⁺ block via PKC ^{8Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →}	Cognitionseizurespain
Nicotinic acetylcholine receptors	Enhances/prolongs ACh-evoked currents ^{8Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →}	Cognitiondementia
Protein kinase C (PKCα)	Activated (bell-shaped, peak ~10 nM); phosphorylates NMDA receptor ^{8Reference 8Moriguchi S et al. · 2007Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptorView study →}	CognitionLTP
CaMKII / CaMKI / CaMKIV → CREB	Activated; restores LTP and phosphorylation in lesioned brain ^{9,10Reference 9Moriguchi S et al. · 2009AnimalNefiracetam activation of CaM kinase II and protein kinase C mediated by NMDA and metabotropic glutamate receptors in olfactory bulbectomized miceView study →Reference 10Han F et al. · 2009AnimalImprovement of depressive behaviors by nefiracetam is associated with activation of CaM kinases in olfactory bulbectomized miceView study →}	Memorymood
Intracellular Ca²⁺ and cAMP	Increased; sustained Ca²⁺ current ^{17Reference 17Kitano Y et al. · 1994General pharmacological profile of the new cognition-enhancing agent nefiracetamView study →}	Neurotransmitter release
GABAergic signalling / GABA transporters	Modulated (secondary, not the primary action); normalises GAT-1/GAT-3 in ischemic brain	Seizuresmood

Pharmacokinetics

Nefiracetam is absorbed rapidly and almost completely after oral dosing in healthy volunteers, reaching peak serum levels within about 1.5–2 hours and showing linear (dose-proportional) kinetics from 10–200 mg ^{6,7Reference 6Fujimaki M et al. · 1992Single- and multiple-dose pharmacokinetics of nefiracetam in healthy volunteersView study →Reference 7Fujimaki Y et al. · 1993Pharmacokinetics of nefiracetam and three metabolites in humans and stereoselective hydroxylation of its pyrrolidine ringView study →}. The parent compound has a short half-life of roughly 3–5 hours and does not accumulate on repeated dosing; food delays absorption but does not materially change overall exposure ^{6Reference 6Fujimaki M et al. · 1992Single- and multiple-dose pharmacokinetics of nefiracetam in healthy volunteersView study →}. Very little is excreted unchanged (<10% in urine); it is cleared mainly by metabolism, and the largest urinary metabolite is a pyrrolidine-ring scission product ^{7Reference 7Fujimaki Y et al. · 1993Pharmacokinetics of nefiracetam and three metabolites in humans and stereoselective hydroxylation of its pyrrolidine ringView study →}. In human liver microsomes, its 5-hydroxylation is carried out chiefly by CYP3A4, with a minor CYP1A2 share ^{18Reference 18Fujimaki Y et al. · 2001Nefiracetam metabolism by human liver microsomes: role of cytochrome P450 3A4 and cytochrome P450 1A2 in 5-hydroxynefiracetam formationView study →}. Several metabolites have substantially longer half-lives (roughly 8–22 hours) than the parent ^{7Reference 7Fujimaki Y et al. · 1993Pharmacokinetics of nefiracetam and three metabolites in humans and stereoselective hydroxylation of its pyrrolidine ringView study →}. Strong CYP3A4 inhibitors or inducers could plausibly alter exposure, though this has not been tested in people.

Clinical trials

Human trial activity is sparse and largely historical: three published double-blind RCTs (post-stroke depression and apathy) and one completed but unreported Phase 2 Alzheimer’s trial (NCT00001933). It is an off-patent investigational drug with essentially no current industry trial activity, and animal toxicity findings (below) discouraged further development in some programs.

Completed	Planned	Terminated	Preclinical
~4	0	0	~100+

Last checked: August 2026.

Dietary Sources

Nefiracetam has no dietary source — it is a fully synthetic pyrrolidone drug, not a nutrient found in food. There is no “natural” nefiracetam to eat and no deficiency state to correct.

How it’s made: it is manufactured synthetically from a 2-oxopyrrolidinyl-acetamide scaffold coupled to a 2,6-dimethylaniline group (the structural feature that distinguishes it from piracetam). It exists in several solid-state forms (a monohydrate and two anhydrate polymorphs) that differ in dissolution and solubility, which matters for formulation rather than for the consumer.

Dosage

There is no established supplement dose and no reference intake — nefiracetam is not a nutrient, so no RDA/AI or Tolerable Upper Intake Level exists. The only human doses on record come from clinical research:

Context	Dose studied	Notes
Post-stroke apathy / depression RCTs	600 or 900 mg/day	The 900 mg/day arm carried the only positive signal; both under medical supervision ^{1,3Reference 1Robinson RG et al. · 2009RCTDouble-blind treatment of apathy in patients with poststroke depression using nefiracetam — randomised controlled trialView study →Reference 3Robinson RG et al. · 2008RCTDouble-blind randomized treatment of poststroke depression using nefiracetam — randomised controlled trialView study →}
Alzheimer’s Phase 2 (NCT00001933)	investigational	No published positive result ^{4Reference 4National Institute of Mental Health · 2002Clinical trialNefiracetam therapy of Alzheimer’s type dementia (Phase 2, completed 2002) — clinical trial recordView study →}
Healthy-volunteer PK studies	10–200 mg single; 200 mg ×3/day	Used to characterise kinetics, not efficacy ^{6Reference 6Fujimaki M et al. · 1992Single- and multiple-dose pharmacokinetics of nefiracetam in healthy volunteersView study →}

These are research protocol doses, not personal recommendations. Absorption is rapid and nearly complete; food delays but does not reduce absorption, so timing with meals is not critical for exposure ^{6Reference 6Fujimaki M et al. · 1992Single- and multiple-dose pharmacokinetics of nefiracetam in healthy volunteersView study →}. Because CYP3A4 forms its main oxidative metabolite in laboratory tests, the practical caution is drug-interaction risk rather than a defined ceiling.

Safety

Nefiracetam’s safety profile is the decision-relevant part, and it is not reassuring for casual use.

Safety at a Glance

Moderate toxicityDrug interactions

Never approved as a medicine or a supplement, anywhere. There is no regulated human safety dossier for over-the-counter exposure.
Testicular toxicity in two species. High oral doses caused seminiferous-tubule atrophy, falling testosterone and malformed sperm in dogs and rats — a real concern for a compound marketed to young men.
Renal papillary necrosis in dogs at 300 mg/kg/day, tied to a dog-specific metabolite. Human relevance uncertain, but it flagged the compound during development.
CYP3A4 interactions are plausible. CYP3A4 forms its main oxidative metabolite in laboratory tests, so strong inhibitors could raise exposure and inducers lower it. None of this has been studied in people.
CNS-depressant effects in animals — ataxia, reduced locomotion, potentiated anaesthesia, transient falls in blood pressure at higher doses.
No upper limit is set. It is not a nutrient; the highest studied human dose is 900 mg/day under supervision.

Full Safety & Interactions Detail

It is an unapproved investigational drug, never cleared as a medicine or a dietary supplement anywhere, so there is no regulated human safety dossier for OTC exposure. Its general pharmacology in animals includes CNS-depressant effects (ataxia, reduced locomotion, potentiation of anaesthesia) and transient falls in blood pressure at higher doses ^{17Reference 17Kitano Y et al. · 1994General pharmacological profile of the new cognition-enhancing agent nefiracetamView study →}.

The most serious signals come from repeat-dose animal toxicology:

Testicular toxicity. In beagle dogs, high oral doses (180–300 mg/kg/day) lowered testicular and serum testosterone after a single dose and produced seminiferous-tubule atrophy, reduced sperm motility and malformed sperm after 4 weeks ^{14Reference 14Shimomura K et al. · 2004Testicular toxicity induced in dogs by nefiracetam, a neurotransmission enhancerView study →}. Rats showed the same pattern (spermatid/spermatocyte degeneration, falling testosterone) at 1500 mg/kg/day ^{15Reference 15Shimada M et al. · 2003AnimalInvestigation of testicular toxicity of nefiracetam, a neurotransmission enhancer, in ratsView study →}. These doses are far above human exposures, but the mechanism — impaired Leydig-cell testosterone synthesis — is a genuine concern for a compound sold to young men.
Renal papillary necrosis. This was dog-specific — not seen in rats or monkeys — at 300 mg/kg/day, and appears tied to a dog-specific metabolite (M-18) and low baseline renal prostaglandin synthesis ^{16Reference 16Tsuchiya Y et al. · 2003Comprehensive evaluation of canine renal papillary necrosis induced by nefiracetam, a neurotransmission enhancerView study →}. Human relevance is uncertain but it flagged the compound for close monitoring.

Drug interactions: in human liver microsomes, nefiracetam’s 5-hydroxylation is carried out chiefly by CYP3A4, with a minor CYP1A2 share ^{18Reference 18Fujimaki Y et al. · 2001Nefiracetam metabolism by human liver microsomes: role of cytochrome P450 3A4 and cytochrome P450 1A2 in 5-hydroxynefiracetam formationView study →}. On that basis, strong CYP3A4 inhibitors (ketoconazole, clarithromycin, ritonavir, grapefruit) might raise exposure and inducers (rifampicin, carbamazepine, St John’s wort) might lower it. Additive CNS depression with sedatives or alcohol is plausible from its animal profile. None of this has been formally studied in people taking it as a supplement.

Scope disclosure. Interactions assessed? Partially — CYP3A4/1A2 metabolism is documented in human liver microsomes, predicting the interactions above, but no dedicated human interaction trials exist. Pregnancy/lactation assessed? No human data, and animal reproductive toxicity is documented. Upper limit established? No — and absence of a UL does not imply any amount is safe. Nefiracetam’s long-term human safety is simply unknown; the animal toxicology is a caution, not a clean bill.

Pregnancy & Lactation

Avoid in pregnancy Avoid while breastfeeding

Avoid. There are no human pregnancy or lactation safety data, and this is an unapproved drug with demonstrated animal reproductive (testicular) toxicity. It should not be used in pregnancy, when trying to conceive, or while breastfeeding.

Related racetams: piracetam, aniracetam, oxiracetam, pramiracetam, phenylpiracetam, coluracetam and fasoracetam.

References

Robinson RG, Jorge RE, Clarence-Smith K, Starkstein S. (2009). Double-blind treatment of apathy in patients with poststroke depression using nefiracetam — randomised controlled trial. The Journal of Neuropsychiatry and Clinical Neurosciences. https://pubmed.ncbi.nlm.nih.gov/19622685/
Starkstein SE, Brockman S, Hatch KK, et al. (2016). A randomized, placebo-controlled, double-blind efficacy study of nefiracetam to treat poststroke apathy — randomised controlled trial. Journal of Stroke and Cerebrovascular Diseases. https://pubmed.ncbi.nlm.nih.gov/26915605/
Robinson RG, Jorge RE, Clarence-Smith K. (2008). Double-blind randomized treatment of poststroke depression using nefiracetam — randomised controlled trial. The Journal of Neuropsychiatry and Clinical Neurosciences. https://pubmed.ncbi.nlm.nih.gov/18451188/
National Institute of Mental Health. Nefiracetam therapy of Alzheimer’s type dementia (Phase 2, completed 2002) — clinical trial record. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT00001933
Ruiz-Franco ML, Amaya-Pascasio L, Gil-Rodríguez M, et al. (2025). Treatment of apathy in stroke patients — systematic review. Frontiers in Neurology. https://pubmed.ncbi.nlm.nih.gov/41383225/
Fujimaki M, et al. (1992). Single- and multiple-dose pharmacokinetics of nefiracetam in healthy volunteers. The Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/1360528/
Fujimaki Y, Sudo K, Hakusui H (1993). Pharmacokinetics of nefiracetam and three metabolites in humans and stereoselective hydroxylation of its pyrrolidine ring. Xenobiotica. https://pubmed.ncbi.nlm.nih.gov/8484264/
Moriguchi S, Shioda N, Maejima H, et al. (2007). Nefiracetam potentiates NMDA receptor function via protein kinase C activation and reduces magnesium block of the NMDA receptor. Molecular Pharmacology. https://pubmed.ncbi.nlm.nih.gov/17095583/
Moriguchi S, et al. (2009). Nefiracetam activation of CaM kinase II and protein kinase C mediated by NMDA and metabotropic glutamate receptors in olfactory bulbectomized mice. Journal of Neurochemistry. https://pubmed.ncbi.nlm.nih.gov/19457128/
Han F, Nakano T, Yamamoto Y, et al. (2009). Improvement of depressive behaviors by nefiracetam is associated with activation of CaM kinases in olfactory bulbectomized mice. Brain Research. https://pubmed.ncbi.nlm.nih.gov/19233146/
Trujillo CA, et al. (2021). Pharmacological reversal of synaptic and network pathology in human MECP2-KO neurons and cortical organoids. EMBO Molecular Medicine. https://pubmed.ncbi.nlm.nih.gov/33501759/
Rashid MH, Ueda H (2002). Nonopioid and neuropathy-specific analgesic action of the nootropic drug nefiracetam in mice. The Journal of Pharmacology and Experimental Therapeutics. https://pubmed.ncbi.nlm.nih.gov/12235255/
Lu XC, Dave JR, Chen Z, et al. (2013). Nefiracetam attenuates post-ischemic nonconvulsive seizures in rats and protects neuronal cell death induced by veratridine and glutamate. Life Sciences. https://pubmed.ncbi.nlm.nih.gov/23603142/
Shimomura K, Shimada M, Hagiwara M, et al. (2004). Testicular toxicity induced in dogs by nefiracetam, a neurotransmission enhancer. Reproductive Toxicology. https://pubmed.ncbi.nlm.nih.gov/15082078/
Shimada M, Shikanai Y, Shimomura K, et al. (2003). Investigation of testicular toxicity of nefiracetam, a neurotransmission enhancer, in rats. Toxicology Letters. https://pubmed.ncbi.nlm.nih.gov/12849691/
Tsuchiya Y, Takahashi Y, Jindo T, et al. (2003). Comprehensive evaluation of canine renal papillary necrosis induced by nefiracetam, a neurotransmission enhancer. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/12954368/
Kitano Y, Makino M, Usui C, et al. (1994). General pharmacological profile of the new cognition-enhancing agent nefiracetam. Arzneimittel-Forschung. https://pubmed.ncbi.nlm.nih.gov/8018090/
Fujimaki Y, Arai N, Nakazawa T, et al. (2001). Nefiracetam metabolism by human liver microsomes: role of cytochrome P450 3A4 and cytochrome P450 1A2 in 5-hydroxynefiracetam formation. The Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/11428655/

For half-lives, timing and stacking across the nootropics on this site, see the Nootropic Dosage Guide.