Glutamate: nootropics and compounds | sci-wiki

Aniracetam

Aniracetam is a fat-soluble member of the racetam family and one of the original ampakines, a positive allosteric modulator of AMPA-type glutamate receptors used as a cognition enhancer. By slowing the desensitization of these excitatory receptors it strengthens the synaptic transmission tied to learning and memory, and it has been used clinically abroad for cognitive symptoms after stroke and in dementia. Its principal metabolite, 2-pyrrolidinone, has been reported to produce a longer-lasting enhancement of AMPA-receptor function through a CaMKII-dependent pathway. It is also noted for anxiolytic and mood effects in animal models.

2 outlets

Nootropic

Memantine

Memantine (brand names Namenda and Ebixa) is an NMDA receptor antagonist approved for moderate to severe Alzheimer's disease; it calms excess glutamate signaling to protect neurons while leaving the normal signaling needed for memory and learning intact [1][2]. What makes it unusual is its voltage-dependent, fast-off-rate binding; it blocks the constant, low-level 'noise' of glutamate but steps aside when a real learning signal arrives, so it doesn't cloud cognition the way stronger blockers (like ketamine) do. It is also more than a pure NMDA blocker; at or near therapeutic brain concentrations it reaches a spread of remote targets, agonizing the high-affinity state of the dopamine D2 receptor, antagonizing 5-HT3 serotonin receptors and several nicotinic acetylcholine receptors (alpha-7, alpha-4/beta-2, alpha-3/beta-4 and alpha-9/alpha-10), and weakly engaging sigma-1 receptors; see the affinity table below for the full fingerprint. Beyond Alzheimer's it is being investigated for a range of conditions; it shows the most promise for the negative symptoms of schizophrenia (social withdrawal, apathy, blunted motivation) and as a mood stabilizer in bipolar disorder, with earlier signals in ADHD (often as an adjunct to a stimulant), anxiety and OCD, and autism.

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Nootropic

Oxiracetam

Oxiracetam is a synthetic compound from the racetam family and a close chemical relative of piracetam; it was developed in Italy in the 1980s as a prescription drug for memory and attention problems in dementia. Older European trials in dementia patients generally reported small improvements on cognitive test scores, but the modern evidence is split: a 590-patient Chinese trial in traumatic brain injury found a real benefit, while a 500-patient Korean trial found none for preventing cognitive decline after stroke, and South Korea then withdrew the drug. Nobody has established how it works; a standard 19-target receptor screen found no measurable binding at concentrations up to 30 micromolar, and no binding constant for oxiracetam at any brain receptor exists in the published literature. It remains in clinical use in China and is sold elsewhere as an unapproved powder, with a mild side-effect record but no trial evidence at all that it improves cognition in healthy people.

3 outlets

Nootropic

Fasoracetam

Fasoracetam is a racetam-class nootropic that acts on the glutamatergic and GABAergic systems; with repeated administration it up-regulates GABA-B and metabotropic glutamate (mGluR) receptors. It is one of relatively few racetams to have reached controlled human trials, having been evaluated in adolescents with attention-deficit hyperactivity disorder who carry variants in genes governing mGluR signaling. It remains an investigational compound and is not an approved medicine.

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Nootropic

Piracetam

Piracetam is the original nootropic, the very compound for which the word 'nootropic' was coined, developed by Corneliu Giurgea in the late 1960s to enhance learning and memory [1]. A cyclic derivative of the neurotransmitter GABA, it has become the foundational template of the entire racetam family and remains one of the most widely studied cognitive enhancers in the world [1][4]. Prized for a remarkable safety record and effects that are most pronounced when brain function is impaired, piracetam supports memory, learning, and cerebral circulation, and is used clinically for cognitive decline, myoclonus, and stroke recovery [2][4][5].

3 outlets

Nootropic

TAK-653

TAK-653, also called osavampator or NBI-1065845, is an experimental oral drug that makes the brain's main excitatory receptor, the AMPA glutamate receptor, respond more strongly to glutamate the brain is already releasing; crucially it cannot switch the receptor on by itself, a design choice intended to avoid the seizure risk that stopped earlier drugs of this type. It is being developed as a fast-acting antidepressant for people whose depression has not responded to standard antidepressants. A 183-person Phase 2 trial found that 1 mg once daily beat placebo on a standard depression rating scale while 3 mg did not reach statistical significance, and five Phase 3 trials are now enrolling; those Phase 2 results have not yet been published in a peer-reviewed journal. It is approved nowhere in the world, it is not a legal supplement, and the entire published literature amounts to about ten papers, most of them written by employees of the companies that own it.

2 outlets

Nootropic

RGPU-95

RGPU-95 is an experimental compound studied in Russian pharmacological research as a structural analog of fenotropil, better known as phenylpiracetam, a nootropic of the racetam family. In animal experiments it has shown anxiety-reducing and antidepressant-like effects, in some measures exceeding those of its parent compound. It is an obscure investigational substance with essentially no human data, and it is not an approved medicine or recognized supplement ingredient anywhere.

1 outlet

Supplement

NAC

N-acetylcysteine (NAC) is one of the most versatile and well-evidenced antioxidant compounds available, prized as a direct precursor to glutathione, the body's master intracellular antioxidant. Beyond replenishing glutathione to counter oxidative stress, it fine-tunes glutamate signaling through the cystine-glutamate antiporter, a mechanism that has driven serious clinical research across psychiatry and neurology [1][3]. It is a decades-old hospital staple, serving as the standard antidote for acetaminophen overdose and as a proven mucolytic, all at low cost and with an excellent tolerability record.

5 outlets

Nootropic

Nooglutyl

Nooglutyl (N-(5-hydroxynicotinoyl)-L-glutamic acid) is a memory-oriented nootropic developed at the Zakusov Institute of Pharmacology, the Russian laboratory also associated with Noopept and Semax. Radioligand studies identify it as a direct positive modulator of AMPA-subtype glutamate receptors, competing with selective AMPA agonists at low micromolar concentrations, which links it mechanistically to the fast excitatory signaling that underlies learning and synaptic plasticity. Across diverse rodent models of amnesia, including those induced by hypoxia, electroconvulsive shock, and cerebral trauma, it produced consistent anti-amnesic effects, and it additionally displayed neuroprotective, antihypoxic, and antioxidant activity in models of ischemic and hemorrhagic stroke. Notably, it improved behavior and memory retrieval in senescence-accelerated (SAMP10) mice, extending interest toward age-related cognitive decline. It remains an investigational compound characterized largely in preclinical research.

2 outlets

Nootropic

Unifiram

Unifiram (DM232) is an exceptionally potent synthetic nootropic developed by Italian medicinal chemists as a next-generation cognition enhancer. Structurally related to the ampakines and to piracetam, it was reported in preclinical studies to be roughly four orders of magnitude more potent than piracetam at reversing memory impairment. This remarkable potency, paired with an ampakine-like boost to learning circuitry, has made unifiram a headline compound in the research-chemical nootropic scene.

1 outlet

Nootropic

Sunifiram

Sunifiram (DM-235) is a synthetic nootropic structurally related to piracetam but dramatically more potent, active at very low doses. It enhances learning and memory by acting on the glycine site of the NMDA receptor and strengthening AMPA-mediated signaling through the CaMKII and PKC pathways, the molecular basis of long-term potentiation. In animal studies it improves cognition and reverses drug-induced amnesia at doses roughly a thousandfold lower than classic racetams, making it one of the most potent research nootropics of its kind.

2 outlets

Nootropic

IDRA-21

IDRA-21 is a small synthetic molecule derived from the blood pressure drug diazoxide. It does not switch brain receptors on by itself; instead it makes the AMPA receptor, which handles the brain's main fast excitatory signal, stay open longer once that natural signal arrives. Oral dosing improved memory scores in rats and in three separate monkey studies, which is why it is sold as a research chemical marketed for cognition. The evidence stops there; no person has ever been studied in a published trial, no clinical trial is registered, and no dose, blood level or side effect profile in humans has ever been reported. One rat study found it made hippocampal cell death after a stroke-like insult worse rather than better, so the safety picture is genuinely open.

1 outlet

Blend

Dextromethorphan + Bupropion

Dextromethorphan/bupropion is a fixed-dose combination medicine used to treat major depressive disorder in adults. Sold under the brand name Auvelity and developed by Axsome Therapeutics, it was approved by the United States Food and Drug Administration in 2022. The product pairs dextromethorphan, which blocks NMDA glutamate receptors and activates sigma-1 receptors, with bupropion, an established antidepressant that also slows the breakdown of dextromethorphan so that useful levels are maintained. It is taken as an extended-release oral tablet and is a prescription medicine that is not a controlled substance.

1 outlet

Antidepressant

(2R,6R)-Hydroxynorketamine

(2R,6R)-Hydroxynorketamine is a downstream metabolite of ketamine, and it is the compound at the centre of the most interesting open question in rapid-acting antidepressant research: whether the mood effect can be separated from the dissociation. In mice, a single dose produces the same antidepressant-like changes as ketamine itself [1], yet at the concentrations that produce them it does not measurably block the NMDA receptor [2]. If that holds, the antidepressant action and the anesthetic, dissociative, abuse-prone action are two different drugs wearing one molecule. The catch is that the behavioural finding has not replicated cleanly, and no human efficacy trial has reported out.

Glutamate

Aniracetam

Memantine

Oxiracetam

Fasoracetam

Piracetam

TAK-653

RGPU-95

NAC

Nooglutyl

Unifiram

Sunifiram

IDRA-21

Dextromethorphan + Bupropion

(2R,6R)-Hydroxynorketamine

2-Arachidonoylglycerol

2-Fluorodeschloroketamine

3-Cl-PCP

3-HO-PCE

3-HO-PCP

3-MeO-PCE

3-MeO-PCMo

3-MeO-PCP

4-MeO-PCP

4-Methylpregabalin

Adamantyl Carbonyl Proline

AMN082

Arketamine

Atagabalin

Basimglurant

Brivaracetam

Cebaracetam

CX-1739

CX-546

CX-614

D-Cycloserine

D-Serine

Deschloroketamine

Dextromethorphan

Dimiracetam

Dipraglurant

Doliracetam

Dupracetam

E-6801

Eglumegad

EMD-386088

Esketamine

Etiracetam

Fenobam

Foliglurax

Galanin(2-11)

HA-966

Hericene A

HU-210

HXE

Idalopirdine

Intepirdine

JNJ-40411813

Ketamine

Latrepirdine

LY341495

LY379268

M617

Masupirdine

Mavoglurant

Methoxetamine

Mibampator

MTEP

MXiPr

NAX 810-2

NAX-5055

Neboglamine

Nicotine

Nitrous oxide

NMDA

Norketamine

O-PCE

Orphenadrine

Pomaglumetad methionil

Ralmitaront