Cognitive and nootropic peptides

Cognitive • Synthetic Semax analog / nootropic research • Experimental

Adamantane-modified Semax analog researched for neurotrophic signaling and peptide stability. No FDA approval; human PK is not established.

Cognitive • Peptide hydrolysate / nootropic research • Experimental

Peptide hydrolysate prepared from porcine brain tissue, supplied as a mixture of low-molecular-weight peptides and free amino acids rather than a single characterised compound. It is used in several countries in Europe and Asia for stroke, traumatic brain injury and dementia, where it is given by injection. Not FDA-approved in the United States, and because it is a mixture its composition is not standardised the way a single-entity drug would be.

Cognitive • Khavinson peptide bioregulator / research • Experimental

Peptide preparation derived from brain and central nervous system tissue and marketed as a tissue-specific bioregulator in the Khavinson tradition. Not FDA-approved for any indication. No controlled human efficacy trials of this specific preparation have been published; the available literature is class-level work on short peptide bioregulators.

Cognitive • Khavinson cortical bioregulator / research • Experimental

Ala-Glu-Asp-Pro, a synthetic tetrapeptide in the Khavinson bioregulator series associated with cerebral cortex tissue. Reported findings concern cortical neuron protein synthesis and nerve regeneration in animal models, published largely in Russian-language journals by a single research group without independent replication. No controlled human evidence exists, and it is not FDA-approved.

Cognitive • Brain polypeptide extract / research • Experimental

Cattle-cortex polypeptide extract used in some CIS countries as a nootropic. Not FDA-approved; composition is a hydrolysate, not a single peptide.

Cognitive • Khavinson bioregulator / research • Experimental

Peptide preparation extracted from brain tissue and sold as a central nervous system bioregulator in the Khavinson tradition. It is a complex of low-molecular-weight peptides rather than a single defined molecule, so no specific sequence or mechanism can be assigned and batch composition is not standardised. Evidence is limited to older bioregulator literature, and it is not FDA-approved.

Cognitive • Neuroprotective octapeptide / discontinued • Emerging

Eight-amino-acid fragment of activity-dependent neuroprotective protein, investigated for tauopathies. A phase 3 trial in progressive supranuclear palsy did not meet its endpoints and development for that indication stopped. Not FDA-approved.

Cognitive • Sleep / neuropeptide research • Experimental

Nonapeptide first isolated from the cerebral venous blood of rabbits during induced slow-wave sleep and named for that association. Its physiological role remains genuinely unsettled: no specific receptor has been identified, reported effects on sleep architecture are inconsistent across studies, and its ability to cross the blood-brain barrier is debated. Research use only and not FDA-approved.

Cognitive • Angiotensin IV analog / nootropic research • Experimental

Orally active angiotensin IV analog that potentiates HGF/c-Met signaling in animal memory models. Not FDA-approved; human safety is not established.

Cognitive • Mitochondrial-derived peptide / research • Experimental

A 24-amino-acid peptide encoded within the mitochondrial 16S ribosomal RNA gene and one of the first mitochondrial-derived peptides described. It has been studied for cytoprotective signalling, particularly resistance to apoptosis and to oxidative and amyloid stress, and for effects on insulin sensitivity. Circulating concentrations decline with age, which drives much of the interest in it. Research use only, with no human interventional trials and no FDA-approved use.

Cognitive • Longevity protein / research • Experimental

Transmembrane and soluble anti-aging protein that is an FGF23 co-receptor. Shop “Klotho” vials are not an FDA-approved drug and are often fragments or poorly characterized proteins.

Cognitive • Phenothiazine redox agent / approved for methaemoglobinaemia • Established

Phenothiazine dye approved as an intravenous treatment for acquired methaemoglobinaemia. It is separately sold as a research chemical and studied at low doses for mitochondrial and cognitive endpoints, which are not approved uses.

Cognitive • Modified Selank analog / research • Experimental

Chemically modified analog of Selank with N-terminal acetylation and C-terminal amidation, sold as a research chemical and commonly used intranasally. Not FDA-approved. Published research on this modified form specifically is very limited; most available data concerns Selank itself.

Cognitive • Modified Semax analog / research • Experimental

N-acetylated, C-amidated Semax analog sold for nootropic research, intended to resist peptidases versus standard Semax. Not FDA-approved.

Cognitive • Dipeptide nootropic / research • Experimental

Synthetic dipeptide developed in Russia and marketed there as a nootropic. It is not FDA-approved and is not a lawful dietary supplement ingredient in the United States. Most published research is Russian-language and preclinical.

Cognitive • Endogenous wake-promoting neuropeptide / research • Experimental

Endogenous 33-amino-acid hypothalamic neuropeptide central to arousal and wakefulness. Loss of orexin-producing neurons causes narcolepsy type 1. Studied as an intranasal research compound; not FDA-approved.

Cognitive • Neurotrophic fragment / research • Experimental

Short nootropic peptide associated with Cerebrolysin-derived fragments in research catalogs. Distinct from the p21 CDK inhibitor protein. Not FDA-approved.

Fat Loss • Endogenous neuropeptide / research • Experimental

38-aa neuropeptide that activates PAC1/VPAC receptors. Research tool in migraine, neuroprotection, and metabolic models. Not FDA-approved as a drug.

Cognitive • TREK-1 research peptide • Experimental

Shortened analog of spadin, a peptide derived from sortilin maturation, which blocks the TREK-1 potassium channel. Because mice lacking TREK-1 show a depression-resistant phenotype, the channel became an antidepressant target, and PE-22-28 produces antidepressant-like effects in rodents within days rather than the weeks required by monoamine reuptake inhibitors. Preclinical only, with no human trials, and not FDA-approved.

Cognitive • Khavinson pineal tripeptide / research • Experimental

Glu-Asp-Arg tripeptide from the Khavinson pineal series, studied for neuroprotection in older literature. Not FDA-approved.

Cognitive • Anxiolytic tuftsin analog / research • Experimental

Synthetic heptapeptide combining the immunomodulatory tetrapeptide tuftsin with a stabilising tail, developed in Russia as an anxiolytic and most often used intranasally. It has been studied for anxiety without the sedation or dependence associated with benzodiazepines, and retains some immune-modulating activity from its tuftsin origin. Not FDA-approved; the supporting clinical literature is largely Russian-language.

Cognitive • ACTH fragment nootropic / research • Experimental

Synthetic analog of the ACTH(4-10) fragment with a stabilising tail added, developed in Russia and used there as an intranasal nootropic and neuroprotective agent for stroke and cognitive indications. It has no corticotropic activity despite its ACTH origin. Reported activity centres on brain-derived neurotrophic factor expression and monoamine modulation. Not FDA-approved, and the clinical literature is almost entirely Russian-language with limited independent replication.