Peptide Encyclopedia
44 compounds across 14 scientific families. Every entry states its compound class and how far it has actually been studied, because those two facts change how everything else on the page should be read.
Identifier verification in progress. 5 of 44 entries currently publish verified identifiers such as CAS number, molecular formula or sequence, each with its source and the date it was checked. The remainder show “not verified” rather than an unchecked figure.
44 compounds
Abaloparatide
An analogue of parathyroid-hormone-related protein, approved for osteoporosis, with receptor-conformation selectivity distinguishing it from teriparatide.
Bone & musculoskeletal
Afamelanotide
An MC1R-selective alpha-MSH analogue approved for a rare photosensitivity disorder. Distinct from Melanotan II despite the shared informal naming.
Melanocortin system
Atrial natriuretic peptide (ANP)
A 28-residue peptide released from atrial myocytes in response to stretch, central to the regulation of sodium and fluid balance.
Cardiovascular & renal signalling
B-type natriuretic peptide (BNP)
A cardiac natriuretic peptide released in response to ventricular wall stress. Principally important clinically as a diagnostic biomarker rather than as a therapeutic.
Cardiovascular & renal signalling
BPC-157
A synthetic fifteen-residue peptide whose sequence derives from a protein found in human gastric juice. Widely studied in rodent injury models; the human evidence base is very thin and it is not an approved medicine anywhere.
Tissue repair & regeneration
Cagrilintide
A long-acting amylin receptor agonist studied both alone and in combination with GLP-1 receptor agonists. Investigational; no marketing authorisation recorded as of this entry’s review date.
Metabolic & incretin research
CJC-1295
A growth-hormone-releasing hormone analogue. The name is used for two materially different compounds — one bearing a drug-affinity complex (DAC) that greatly extends half-life, and one without it — and conflating them is the most common error in writing about this molecule.
Growth hormone axis & secretagogues
Delta sleep-inducing peptide (DSIP)
A nonapeptide originally isolated from rabbit cerebral venous blood during induced sleep states. Despite the name, its role in sleep regulation has never been firmly established.
Neuroscience & neuroactive peptides
Desmopressin
A vasopressin analogue selective for the V2 receptor, used clinically in diabetes insipidus and certain bleeding disorders.
Reproductive & endocrine signalling
Epithalon
A synthetic tetrapeptide (Ala-Glu-Asp-Gly) associated with research from a single Russian research tradition into pineal peptide preparations and ageing.
Longevity & experimental biology
Exenatide
A 39-residue peptide originally identified in the venom of the Gila monster, Heloderma suspectum, which acts as a GLP-1 receptor agonist. Historically important as the first incretin mimetic to reach the clinic.
Metabolic & incretin research
FOXO4-DRI
A D-retro-inverso peptide designed to disrupt the FOXO4–p53 interaction, studied as a senolytic in laboratory models.
Longevity & experimental biology
GHK-Cu
A complex of the tripeptide glycyl-histidyl-lysine with copper(II). Classified here as a metal–peptide complex rather than a peptide, because the copper ion is integral to the species and to its reported chemistry.
Dermatology & cosmetic science
GHRP-2
A synthetic hexapeptide ghrelin receptor agonist, used in some jurisdictions as a diagnostic agent for growth hormone secretion.
Growth hormone axis & secretagogues
GHRP-6
An early synthetic hexapeptide secretagogue acting at GHS-R1a. Historically important in the discovery of the ghrelin receptor system.
Growth hormone axis & secretagogues
Gonadorelin
Synthetic gonadotropin-releasing hormone, identical to the native decapeptide. Used diagnostically and historically therapeutically.
Reproductive & endocrine signalling
Hexarelin
A synthetic hexapeptide secretagogue, also studied for reported cardiac effects independent of growth hormone release.
Growth hormone axis & secretagogues
Humanin
The first mitochondrial-derived peptide to be identified, encoded within the mitochondrial 16S rRNA gene.
Mitochondrial & cellular bioenergetics
Ipamorelin
A pentapeptide ghrelin receptor agonist. Acts at GHS-R1a, a different receptor from the GHRH analogues it is frequently paired with in discussion.
Growth hormone axis & secretagogues
Isotopically labelled peptides
Peptides synthesised with heavy isotopes, typically carbon-13 and nitrogen-15, used as internal standards in quantitative mass spectrometry.
Laboratory & analytical materials
Kisspeptin-10
The C-terminal decapeptide of kisspeptin, the ligand for the KISS1R receptor and an upstream regulator of GnRH release.
Reproductive & endocrine signalling
KPV
The C-terminal tripeptide of alpha-MSH, studied for anti-inflammatory activity apparently independent of melanocortin receptor binding.
Antimicrobial, immune & host defence
Leuprolide
A long-acting GnRH agonist that produces sustained suppression of the reproductive axis through receptor downregulation. A widely used medicine in oncology and endocrinology.
Reproductive & endocrine signalling
Liraglutide
A fatty-acylated GLP-1 analogue with a once-daily profile, approved as a medicine in multiple jurisdictions and extensively characterised in the literature.
Metabolic & incretin research
LL-37
The only human cathelicidin, released by proteolytic processing of the precursor hCAP18. A central molecule in innate immunity and in antimicrobial peptide research.
Antimicrobial, immune & host defence
Melanotan II
A cyclic heptapeptide analogue of alpha-MSH acting non-selectively across several melanocortin receptor subtypes. Associated with documented safety concerns in unsupervised use.
Melanocortin system
MOTS-c
A mitochondrial-derived peptide encoded within the mitochondrial 12S rRNA gene rather than the nuclear genome — a class of molecule only recognised comparatively recently.
Mitochondrial & cellular bioenergetics
Oxytocin
A posterior pituitary nonapeptide with a disulfide bridge, among the earliest peptide hormones characterised and synthesised. An established medicine in obstetric practice.
Reproductive & endocrine signalling
Peptide reference standards
Characterised materials of known identity and assigned purity, used to calibrate analytical methods and to confirm the identity of test articles by comparison.
Laboratory & analytical materials
Pramlintide
A synthetic analogue of human amylin with proline substitutions that prevent the aggregation which makes native human amylin impractical as a therapeutic.
Gastrointestinal & appetite signalling
PT-141 (bremelanotide)
A melanocortin receptor agonist, structurally related to Melanotan II, which has received marketing authorisation in at least one jurisdiction for a specific indication.
Melanocortin system
Retatrutide
An engineered single-molecule agonist at the GIP, GLP-1 and glucagon receptors, developed by Eli Lilly under the code LY3437943. It is investigational: it has been studied in human trials but is not an approved medicine in any jurisdiction as of this entry’s review date.
Metabolic & incretin research
Selank
A synthetic heptapeptide based on the immunomodulatory peptide tuftsin, extended with Pro-Gly-Pro for stability. Studied principally for anxiolytic-related effects.
Neuroscience & neuroactive peptides
Semaglutide
A long-acting GLP-1 receptor agonist, structurally derived from human GLP-1 with modifications that resist enzymatic degradation and extend circulating half-life. Approved as a medicine in multiple jurisdictions.
Metabolic & incretin research
Semax
A synthetic heptapeptide derived from a fragment of ACTH with a C-terminal Pro-Gly-Pro extension that confers enzymatic stability. Developed and studied largely in Russia, where it has had regional regulatory status.
Neuroscience & neuroactive peptides
Sermorelin
The first 29 residues of human growth-hormone-releasing hormone — the shortest fragment retaining full activity at the GHRH receptor. Has held marketing authorisation as a diagnostic and therapeutic agent.
Growth hormone axis & secretagogues
SS-31 (elamipretide)
A short synthetic tetrapeptide with an alternating aromatic-cationic motif that associates with cardiolipin in the inner mitochondrial membrane. Investigational, with a substantial clinical trial record.
Mitochondrial & cellular bioenergetics
TB-500 (thymosin beta-4 fragment)
A synthetic peptide corresponding to an active region of thymosin beta-4. Frequently conflated with full-length thymosin beta-4, which is a different and longer molecule — the two should not be treated as interchangeable.
Tissue repair & regeneration
Teriparatide
The N-terminal 34 residues of human parathyroid hormone, an approved anabolic osteoporosis medicine and a clean illustration of dose-schedule dependence in pharmacology.
Bone & musculoskeletal
Tesamorelin
A stabilised GHRH analogue carrying a trans-3-hexenoyl group at the N-terminus, approved in some jurisdictions for a specific indication.
Growth hormone axis & secretagogues
Thymosin alpha-1
A 28-residue thymic peptide with immunomodulatory activity, approved in some jurisdictions as thymalfasin.
Antimicrobial, immune & host defence
Tirzepatide
A dual agonist at the GIP and GLP-1 receptors. Unlike most compounds in this encyclopedia, tirzepatide has received marketing authorisation as a medicine in several jurisdictions, which means a regulator has reviewed a full clinical dossier for it.
Metabolic & incretin research
Triptorelin
A GnRH agonist carrying a D-tryptophan substitution at position 6, giving greatly increased potency and duration relative to native GnRH. An approved medicine in many jurisdictions.
Reproductive & endocrine signalling
Vasopressin
The posterior pituitary nonapeptide governing water reabsorption and vascular tone. Differs from oxytocin by only two residues.
Reproductive & endocrine signalling