🧠 Brain & Nervous System peptides

A Lilly investigational peptide candidate being studied in alcohol use disorder, mood disorders, and other craving-linked conditions.

A high-curiosity neurotrophic research peptide discussed for cognition and synaptogenesis, but still lacking real clinical development.

A recombinant human nerve growth factor produced in E. coli, FDA approved since 2018 as Oxervate eye drops for neurotrophic keratitis, that acts through TrkA and p75 receptors to restore corneal nerve function and epithelial healing.

Synthetic ovine corticotropin-releasing hormone approved in 1996 as Acthrel, a diagnostic injection that distinguishes pituitary from ectopic ACTH secretion in Cushing's syndrome and has been unavailable since its 2020 discontinuation.

A synthetic all-D-amino-acid tetrapeptide that selectively activates peripheral kappa-opioid receptors, FDA approved since 2021 as Korsuva, an intravenous injection given at the end of hemodialysis for moderate-to-severe chronic kidney disease-associated itch.

A peptide hormone used in FDA-approved medical settings but also frequently reframed in wellness and research-market discussions.

A melanocortin peptide best known in regulated medicine as bremelanotide and in the research market as PT-141.

An FDA-approved MC4R agonist marketed as Imcivree for specific rare genetic forms of obesity.

A synthetic, orally bioavailable analog of the IGF-1 N-terminal tripeptide glycine-proline-glutamate, FDA approved in March 2023 as Daybue, the first treatment for Rett syndrome, after earlier programs in traumatic brain injury and fragile X syndrome did not progress.

A synthetic 25-residue omega-conotoxin MVIIA from the cone snail Conus magus that blocks N-type voltage-gated calcium channels; FDA-approved as Prialt (2004) for severe chronic pain by intrathecal infusion only.

A synthetic 15-amino-acid macrocyclic peptide that binds complement C5 and blocks terminal complement activation, FDA approved in October 2023 as Zilbrysq, a once-daily subcutaneous injection for acetylcholine receptor antibody-positive generalized myasthenia gravis.

An erythropoietin-derived peptide fragment studied for tissue-protective and neuropathy-related applications without the red-blood-cell effects of full EPO.

The native 31-residue opioid peptide cleaved from pro-opiomelanocortin in the pituitary and hypothalamus, a mu- and delta-opioid receptor agonist studied by intravenous, intrathecal and epidural routes in small human series around 1980 and never developed into an approved product.

An Austrian prescription injectable made from enzymatically digested pig brain protein — a mixture of sub-10 kDa peptides and free amino acids, approved for stroke, dementia, and head injury in parts of Europe and Asia but never reviewed by the FDA.

A 37-amino-acid sensory neuropeptide and one of the most potent vasodilators described in humans; every FDA-approved drug in this space blocks CGRP rather than supplying it, and the peptide itself has no approved product.

A synthetic eight-amino-acid fragment (NAPVSIPQ) of activity-dependent neuroprotective protein, developed as an intranasal microtubule-stabilizing tau therapy, whose 313-patient phase 2/3 trial in progressive supranuclear palsy was negative on every endpoint.

The C-terminal decapeptide of the KISS1 gene product that activates the KISS1R (GPR54) receptor on hypothalamic GnRH neurons, used in academic human physiology studies and early-phase reproductive-disorder trials; no approved product exists.

An endogenous opioid pentapeptide (Tyr-Gly-Gly-Phe-Leu) isolated from brain in 1975 that preferentially activates delta-opioid receptors, is degraded within minutes by peptidases, and circulates today as a laboratory reference reagent rather than a therapeutic.

An endogenous opioid pentapeptide (Tyr-Gly-Gly-Phe-Met), also called Opioid Growth Factor, studied as a tonic inhibitor of cell proliferation through a non-classical receptor; its small human trials in cancer and autoimmune disease were open-label or terminated, and the one industry development program was abandoned over pharmacokinetics.

A native 13-amino-acid peptide found in the brain and small intestine that signals through the NTS1 and NTS2 receptors and sortilin, studied in humans mainly as a physiology probe and never developed into an approved medicine.

A synthetic, orally active analog of cyclic glycine-proline, an endogenous IGF-1 metabolite, developed by Neuren Pharmaceuticals (proposed INN ercanetide) for Phelan-McDermid, Pitt Hopkins and Angelman syndromes, with a placebo-controlled phase 3 trial in Phelan-McDermid syndrome under way since late 2025.

A 38-amino-acid neuropeptide of the VIP-secretin-glucagon superfamily that signals through PAC1, VPAC1 and VPAC2 receptors; its preclinical record is neuroprotective, while every drug program built on it blocks the peptide rather than supplying it.

An endogenous 11-amino-acid tachykinin encoded by the TAC1 gene that activates the neurokinin-1 receptor in pain, vasodilation and neuroimmune signaling, with no approved product anywhere and only small human provocation studies.

An oral triple monoamine reuptake inhibitor, not a peptide, that produced roughly 10% weight loss in Phase 2 and a Mexican Phase 3 program but remains unapproved everywhere, with dose-related heart-rate increases and a Lancet expression of concern on its key trial.

A large (~130 kDa) glycosylated transmembrane and circulating protein encoded by the KL gene, known for mouse lifespan genetics and a single-dose rhesus macaque cognition study, with no human trial of the protein itself.

A research-market analog of Semax described by its sellers as the Semax heptapeptide acetylated at the N-terminus and capped at the C-terminus with the aminoadamantane unit of Peptide 021; the design has no published synthesis, pharmacology, or human data of its own.

A synthetic tetrapeptide (Ala-Glu-Asp-Pro) from the Khavinson bioregulator program, designed from amino-acid analysis of the Cortexin brain-cortex extract and studied in rodents and tissue culture for cortical explant growth, nerve regeneration, and antioxidant effects.

A neuropeptide related to somatostatin that has been studied for anti-inflammatory, neuroendocrine, and cardiovascular effects.

A heptapeptide from the skin of Phyllomedusa frogs carrying a D-alanine at position 2 and very high mu-opioid receptor selectivity, studied briefly in humans in the 1980s and known since 2012 chiefly as a racehorse doping agent.

An eleven-residue, C-terminally amidated peptide predicted to be cleaved from the prodomain of the glial cell line-derived neurotrophic factor precursor, studied in rat and nonhuman-primate Parkinson's models with no human trials.

A peptide discussed for sleep-related and neuroregulatory interest, though its evidence base is far less concrete than vendor listings suggest.

A 15-residue synthetic peptide copied from the second fibronectin type III module of NCAM that binds and activates FGFR1, studied in rodents for memory, synaptic plasticity, and neuroprotection; under its clinical designation FGLL it completed a single phase 1 study in healthy volunteers.

A synthetic hexapeptide (Thr-Gly-Glu-Asn-His-Arg) corresponding to residues 41–46 of human leukemia differentiation factor, studied almost entirely by one Russian research network — in rodent models of neurodegeneration and, on a separate track, as a tumor-cell differentiating agent — with no human trial anywhere.

A mitochondria-associated peptide frequently discussed in longevity circles for cytoprotective and metabolic-interest pathways.

A 112-amino-acid protein fragment shed from the muscle membrane protein FNDC5, proposed in 2012 as an exercise-induced myokine that browns white fat; its existence, measurement, and function in humans remain disputed, and it has never been administered to people.

A free-acid N-acetylated analog of the Russian anxiolytic peptide Selank, capped at the N-terminus while retaining the native C-terminal carboxyl, sold in the research market with no published studies of its own.

A free-acid N-acetylated analog of Semax, the Russian intranasal nootropic, capped at the N-terminus while retaining the native C-terminal carboxyl; the capped peptide itself has just two published papers, both chemistry-led, and no clinical record.

An N-acetylated, amidated form of Selank designed for enhanced stability and nasal bioavailability, studied for anxiolytic and nootropic effects via tuftsin-related immune modulation.

An N-acetylated, amidated form of Semax designed for enhanced stability, studied for nootropic and neuroprotective effects via BDNF upregulation and melanocortin receptor activity.

An orally active dipeptide-derived small molecule — INN omberacetam — registered as a prescription nootropic in Russia and sold on the Western research market with no randomized or placebo-controlled human trial, no registered clinical study, and no FDA approval.

The native 33-amino-acid hypothalamic neuropeptide whose loss causes narcolepsy type 1, tested intranasally in small narcolepsy studies and in sleep-deprived monkeys, with no approved product anywhere and no registered development program.

A synthetic, orally active ciliary neurotrophic factor peptide mimetic (Ac-DGGLAG-NH2) from Khalid Iqbal's laboratory, studied only in rodent models of Alzheimer's disease, aging and Down syndrome, with no human trials and no regulatory approval.

A seven-amino acid fragment of the neuropeptide spadin, studied as a TREK-1 channel blocker with potential antidepressant-like effects in preclinical models.

A synthetic tripeptide (Glu-Asp-Arg) developed by the Khavinson group as a pineal gland bioregulator, studied for neuroprotective and geroprotective effects.

Injectable complex of water-soluble polypeptide fractions extracted from cattle retina, used in Russian ophthalmology for glaucoma and retinal disease; its evidence base is largely Russian-language clinical literature, with no FDA approval or registered Western trials.

A synthetic peptide associated with anxiolytic and cognitive-interest discussions in nootropic communities.

A synthetic neuropeptide analog often discussed for cognitive and neuroprotection-related interest in research-market circles.

The native 14-amino-acid hypothalamic and gut hormone that inhibits growth hormone, insulin, glucagon and splanchnic blood flow, sold abroad as a hospital infusion for variceal bleeding but never approved in the United States, where octreotide is the clinical analog.

A hypothalamic tripeptide (pGlu-His-Pro-NH2) that triggers pituitary TSH and prolactin release; its two U.S. diagnostic injections are both discontinued, and its neuropsychiatric research record is a long series of rapid but transient effects.

A naturally occurring tetrapeptide, Thr-Lys-Pro-Arg, cut from the Fc region of immunoglobulin G that stimulates macrophage and microglial phagocytosis through neuropilin-1, studied extensively in animal models of demyelination and infection yet never approved anywhere.

A peptide complex extracted from calf cerebral cortex and sold as oral capsules in the Khavinson bioregulator line, distinct from the defined synthetic bioregulator peptides and without any published study naming the product itself.

A Russian prescription injectable made from a water-soluble polypeptide fraction of cattle or pig cerebral cortex, marketed for stroke and encephalopathy — an undefined tissue extract rather than a single peptide, never reviewed by the FDA.

An oral capsule preparation of bovine pineal peptide extract from the Khavinson bioregulator program, marketed as the A-8 counterpart to injectable Epithalamin and distinct from the synthetic tetrapeptide epitalon.