Peptide Database

APLNR ligand · apelin-13

Apelin is an endogenous peptide that acts as the ligand for the APJ receptor (APLNR), a GPCR expressed throughout the cardiovascular system. It improves cardiac output and vascular tone through both positive inotropy and vasodilation, increases nitric oxide production, and reduces oxidative stress. Research focuses on heart failure, pulmonary arterial hypertension, and its potential to replace or complement established cardiac peptides.

FPF 1070

Cerebrolysin is a mixture of neuropeptides and neurotrophic factors derived from porcine brain proteins. It mimics the actions of endogenous neurotrophic factors (NGF, BDNF, CNTF), promoting neuronal survival, synaptogenesis, and neuroplasticity. Approved in multiple countries for Alzheimer's disease, stroke recovery, and TBI, clinical trials show improvements in cognitive function, activities of daily living, and brain MRI outcomes.

Trappin-2 · SKALP

Elafin is an endogenous serine protease inhibitor (serpin-like) peptide produced by epithelial cells at mucosal surfaces. It inhibits neutrophil elastase and proteinase 3, protecting tissues from excessive inflammatory damage, while also exhibiting direct antimicrobial activity against bacteria and fungi. Research focuses on inflammatory bowel disease, cystic fibrosis, ARDS, and vaginal microbiome modulation, where recombinant elafin is in Phase 2 trials.

ET-1 · Big endothelin-1

Endothelin-1 (ET-1) is a 21-amino-acid vasoconstrictor peptide produced primarily by vascular endothelial cells. It is the most potent endogenous vasoconstrictor known, acting through ETA and ETB receptors on vascular smooth muscle and endothelium. Elevated ET-1 is implicated in pulmonary arterial hypertension, heart failure, and renal disease — driving the development of endothelin receptor antagonists (bosentan, ambrisentan, macitentan) as clinical drugs.

Leu-Enkephalin · Met-Enkephalin

Enkephalins are endogenous opioid pentapeptides (Met-enkephalin and Leu-enkephalin) acting as natural ligands for delta and mu opioid receptors. They modulate pain, mood, reward, and immune function. Low-dose naltrexone (LDN) works partly by transiently blocking opioid receptors to upregulate enkephalin production. Methionine enkephalin (met-enkephalin) has shown immune-modulating and anti-tumor properties in research, particularly for HIV and cancer.

Epitalon · Epithalamin

Epithalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) modeled on the endogenous pineal peptide epithalamin. It is one of the most extensively studied longevity peptides, with Russian research demonstrating telomerase activation, telomere elongation, melatonin normalization, and extended lifespan in animal models. Long-term human studies show reduced all-cause mortality rates and improved biomarkers of aging.

FST-344 · Follistatin isoform 344

Follistatin-344 is an isoform of follistatin, an endogenous glycoprotein that binds and neutralizes myostatin (GDF-8) and activin, thereby releasing the natural inhibition on muscle growth. Without myostatin's inhibitory signal, satellite cells proliferate and muscle fiber hypertrophy is dramatically enhanced. Gene therapy studies in animals and in rare myostatin-null humans demonstrate extreme muscle mass increases, driving significant research interest.

Motilin-related peptide · Growth hormone secretagogue

Ghrelin is a 28-amino-acid acylated peptide hormone primarily produced by gastric X/A-like cells and is the endogenous ligand for the growth hormone secretagogue receptor (GHS-R1a). It stimulates GH release, increases appetite and food intake, promotes energy storage, and modulates sleep and mood. Research explores ghrelin axis manipulation for obesity, cachexia, heart failure, and neurodegenerative diseases.

Growth Hormone-Releasing Hormone · Somatoliberin

GHRH is the endogenous 44-amino-acid hypothalamic peptide that drives the pulsatile secretion of growth hormone from the anterior pituitary. Native GHRH acts through GHRHR, stimulating GH gene transcription and secretion. It has a very short half-life in vivo, making it impractical as a therapeutic — which drove the development of modified analogs like sermorelin, CJC-1295, and tesamorelin. Research into GHRH receptor signaling underpins the entire GH secretagogue drug class.

Glucagon-like Peptide-1 · GLP-1(7-37)

GLP-1 is an endogenous incretin hormone secreted by intestinal L-cells in response to nutrient ingestion. It enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and signals satiety to the hypothalamus. Native GLP-1 has a half-life of only 1–2 minutes due to DPP-4 degradation, which drove the development of DPP-4-resistant analogs (semaglutide, liraglutide, exenatide) that are now major drug classes.

GnRH · Gonadotropin-Releasing Hormone

Gonadorelin is a synthetic decapeptide identical to endogenous GnRH. When administered in pulsatile fashion it stimulates LH and FSH release from the pituitary, driving gonadal testosterone and estrogen production. Clinically used for diagnosing hypothalamic-pituitary dysfunction, treating hypogonadotropic hypogonadism, and inducing ovulation. Paradoxically, continuous administration causes receptor downregulation and hormonal suppression — the basis of GnRH agonist therapy in prostate cancer.

KP-10 · metastin 45-54

Kisspeptin-10 is the shortest biologically active fragment of the kisspeptin peptide family, which are potent endogenous activators of the hypothalamic GnRH pulse generator. Research demonstrates it stimulates LH and FSH release and has been studied for infertility, hypogonadotropic hypogonadism, and modulating sexual aversion in psychological studies. It represents a key upstream regulator of the reproductive axis.

NT · NTS

Neurotensin is a 13-amino-acid neuropeptide found in the brain and GI tract. Centrally, it modulates dopamine circuits, acts as an endogenous antipsychotic-like agent, and is analgesic. Peripherally, it inhibits gastric acid secretion, stimulates pancreatic secretion, and promotes fat absorption. Research explores neurotensin analogs for pain, schizophrenia, Parkinson's disease, and metabolic regulation.

N-phenylacetyl-L-prolylglycine ethyl ester · GVS-111

Noopept is a dipeptide-derived nootropic approved in Russia for cognitive disorders and memory impairment. It is hydrolyzed in vivo to release cycloprolylglycine, an endogenous neuropeptide. Research demonstrates neuroprotective, memory-enhancing, and anxiolytic effects, upregulation of BDNF and NGF in the hippocampus and cortex, and potential benefits in Alzheimer's disease models. It is significantly more potent than piracetam on a weight-for-weight basis.

Serelaxin · H2 relaxin

Relaxin-2 is an endogenous peptide hormone structurally related to insulin, primarily known for its role in pregnancy (cervical ripening, joint laxity). Research discovered its potent anti-fibrotic properties — it remodels collagen networks in heart, kidney, lung, and liver — making it a leading candidate for fibrosis and acute heart failure. Serelaxin (recombinant relaxin) reached Phase 3 trials for acute heart failure with promising early signals but did not meet primary endpoints.

GHRH(1-29) · GRF 1-29 NH2

Sermorelin is a synthetic analog of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH). It stimulates the pituitary to produce and secrete growth hormone in a pulsatile, physiologic manner. FDA-approved for GH deficiency in children, it is extensively researched in adults for body composition, sleep quality, and age-related GH decline.

C₁₄₉H₂₄₆N₄₄O₄₂S · 3357.88 Da

SRIF · Somatotropin Release-Inhibiting Factor

Somatostatin is a 14-amino-acid cyclic peptide and the primary endogenous inhibitor of growth hormone secretion. It also inhibits insulin, glucagon, gastrin, cholecystokinin, and secretin release, slows GI motility, and reduces splanchnic blood flow. Its short half-life drove the development of longer-acting analogs (octreotide, lanreotide) used clinically for acromegaly, neuroendocrine tumors, and GI bleeding.

Alpha-Melanocyte-Stimulating Hormone · α-Melanotropin

α-MSH is an endogenous 13-amino-acid peptide derived from POMC (pro-opiomelanocortin). It activates MC1R to stimulate melanin production in skin, MC4R to suppress appetite and regulate energy expenditure, and MC3R/MC1R to exert potent anti-inflammatory effects. It is the parent compound from which many synthetic melanocortin analogs (Melanotan I, II, PT-141, KPV) were derived and remains a cornerstone of melanocortin pharmacology research.