Copper-binding tripeptide (Ala-His-Lys) studied alongside GHK-Cu in skin and hair research
AHK-Cu is a copper-binding tripeptide (Ala-His-Lys) sometimes paired with GHK-Cu in skin and hair research. The peer-reviewed literature directly on AHK / AHK-Cu is more limited than on GHK / GHK-Cu, and several papers focus on the related DAHK (Asp-Ala-His-Lys) human-serum-albumin N-terminal sequence rather than AHK itself.
Limited primary literature; documented as part of the broader copper-tripeptide research alongside GHK-Cu
Modified C-terminal fragment of human growth hormone (hGH 177–191)
AOD-9604 is a modified 16-residue C-terminal fragment of human growth hormone (residues 177–191) with an added N-terminal tyrosine. It was developed in the late 1990s–early 2000s as a candidate anti-obesity compound. Published primary research is dominated by rodent and rabbit models. AOD-9604 is not approved as a medicine.
Preclinical (rodent and rabbit) literature; Phase II clinical interest in early 2000s, limited published trial results
ARA-290 (cibinetide) is an 11-residue peptide derived from the helix B domain of erythropoietin. It engages the innate-repair receptor (a heterodimer of EPO-R and β common receptor) without stimulating erythropoiesis. Phase II clinical evidence exists in small-fibre neuropathy contexts; it is investigational at the time of writing.
Phase II clinical evidence in sarcoidosis small-fibre neuropathy and diabetic neuropathy; investigational
BPC-157 is a synthetic 15-residue peptide fragment derived from a sequence identified in gastric juice. Published research is dominated by rodent and in vitro models; no peer-reviewed controlled human trials have been published.
Cagrilintide is an acylated long-acting analogue of the pancreatic hormone amylin. It is investigational and is most often discussed in the literature alongside semaglutide as the CagriSema combination. The Lau 2021 Phase 2 dose-finding RCT established the monotherapy efficacy and safety profile in obesity.
Phase II clinical evidence published; ongoing Phase III development including the CagriSema (cagrilintide + semaglutide) combination
Khavinson short peptide · Ala-Glu-Asp tripeptide · Preclinical only
Cartalax is a short tripeptide (Ala-Glu-Asp / AED) developed by the Khavinson research group in St Petersburg. Published evidence is preclinical, primarily organotypic and cell-culture work, and is concentrated within the Khavinson network. There are no FDA, MHRA, or EMA approvals.
Preclinical (cell-culture) literature from a single research network
Neuropeptide / amino-acid mixture derived from porcine brain tissue · Approved in multiple jurisdictions (not US/UK); Cochrane evidence is mixed
Cerebrolysin (FPF1070) is a porcine-brain-derived peptide and free-amino-acid mixture marketed by Ever Neuro Pharma. It is approved in many countries (including parts of Europe and Asia) for stroke, traumatic brain injury, and dementia, but is not FDA-approved in the United States. Multiple Cochrane systematic reviews have evaluated the evidence base — the most recent stroke update (2023) reports no mortality benefit and a possible increase in non-fatal serious adverse events.
Multiple Cochrane systematic reviews in stroke and vascular dementia; clinical evidence is mixed
CJC-1295 is a synthetic GHRH analogue investigated in early-phase human pharmacology studies and in GHRH-knockout rodent models. Published primary human research is limited to small Phase I/II pharmacokinetic and pharmacodynamic trials.
Phase I/II human pharmacology and rodent literature
Dermorphin is a seven-residue opioid peptide isolated from the skin of South American Phyllomedusa frogs in the 1980s. It is a highly selective μ-opioid receptor agonist and is approximately 30–40 times more potent than morphine in animal models. Dermorphin and its analogues are research compounds; the parent compound has documented illicit use in horse racing and is treated as a controlled substance for veterinary and anti-doping purposes.
Pharmacology and structure-activity literature from the 1980s onwards; analogue development for analgesia research
Endogenous nonapeptide implicated in delta-sleep induction
DSIP (delta sleep-inducing peptide) is an endogenous nine-residue peptide isolated from rabbit cerebral venous blood during electrical sleep stimulation in the 1970s. Most of the peer-reviewed literature consists of reviews and early-phase research from the 1970s–2000s; modern controlled clinical trials are limited.
Foundational review and early-phase literature from 1970s–2000s; limited recent peer-reviewed primary research
Epitalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) studied in cellular ageing, gene-expression, and telomere-biology models. Most primary literature originates from a small number of research groups; controlled human clinical trials are absent from PubMed-indexed peer-reviewed sources.
In vitro, animal, and limited human cell-line literature
Synthetic D-retro-inverso senolytic peptide · Preclinical only
FOX04-DRI is a D-retro-inverso peptide designed by the Peter de Keizer group (Erasmus / Utrecht) to interfere with the FOXO4-p53 interaction in senescent cells. The intent is to selectively trigger apoptosis of senescent cells (a 'senolytic' approach). All published evidence is preclinical — rodent and in vitro work. There are no peer-reviewed clinical trials in humans.
Preclinical only — no human clinical trials indexed on PubMed
Glycyl-L-histidyl-L-lysine — endogenous tripeptide (uncomplexed form of GHK-Cu)
GHK is the uncomplexed tripeptide form of GHK-Cu — the same sequence (Gly-His-Lys) without bound copper. It is endogenously present in human plasma and declines markedly with age. Most published research discusses GHK in the copper-bound (GHK-Cu) form because the copper binding is central to the proposed mechanisms; this profile distinguishes the uncomplexed peptide for completeness.
Mostly in vitro and topical-formulation literature; serum-level decline with age documented
GHK-Cu is a copper-binding tripeptide complex studied across in vitro, rodent, and topical-cosmetic models, primarily in the context of extracellular matrix and skin biology research.
GHRP-2 is a synthetic six-residue growth hormone-releasing peptide. As pralmorelin, it has been used in Japan as a diagnostic agent for growth hormone deficiency testing. Most peer-reviewed primary research consists of small human pharmacology studies and in vitro / animal mechanism work.
Diagnostic-context approved use in Japan (pralmorelin) for GH-deficiency testing; broader literature is preclinical and small-cohort pharmacology
GHRP-6 is one of the original synthetic growth hormone-releasing peptides (Bowers and colleagues, 1980s). It established the GHRP class and remains a reference compound in receptor pharmacology. A substantial rodent literature has subsequently explored cytoprotective and organ-injury models.
Foundational early-phase pharmacology + sizeable rodent literature on cytoprotection and organ-failure models
Hexarelin is a synthetic six-residue growth hormone-releasing peptide (GHRP). It was developed in the 1990s and is referenced in early-phase human pharmacology studies (often comparing GH-releasing peptides) and a sizeable rodent literature, including cardiovascular and metabolic models. It is not approved as a medicine.
Mixed evidence: small early-phase human pharmacology studies + extensive rodent literature
Recombinant long Arg3 analogue of insulin-like growth factor 1
IGF-1 LR3 is a recombinant analogue of insulin-like growth factor 1 with an N-terminal extension and an arginine substitution at position 3. The modifications reduce binding to IGFBPs (IGF binding proteins) and prolong activity, making LR3 IGF-1 a common reagent in cell-culture and animal-physiology research. It is not approved for human use.
Research and biomanufacturing literature; veterinary in vivo studies; no human therapeutic approval
Ipamorelin is a synthetic pentapeptide ghrelin (GHS-R1a) receptor agonist developed at Novo Nordisk in the late 1990s as a selective growth hormone secretagogue. Published work includes early-phase human pharmacokinetic studies and a body of rodent preclinical literature. Ipamorelin is not approved as a medicine and is not for human use outside of regulated research settings.
Early-phase clinical pharmacokinetic research and preclinical animal literature
Kisspeptin-10 is a C-terminal fragment of the KISS1 gene product that activates the KISS1R (GPR54) receptor. Published research spans cell-based signalling assays, knockout-mouse models, and human reproductive-endocrinology pharmacology studies, alongside emerging bone-biology research.
Receptor signalling and reproductive endocrinology literature
C-terminal tripeptide of α-melanocyte-stimulating hormone (α-MSH 11-13)
KPV is the C-terminal tripeptide fragment of α-melanocyte-stimulating hormone (α-MSH). Research has demonstrated anti-inflammatory activity in models of intestinal inflammation (colitis) and keratinocyte biology, with the PepT1 transporter implicated in cellular uptake.
Active in vitro and rodent inflammation literature; in vivo colitis models and dermatology research
Human cathelicidin antimicrobial peptide (C-terminal cleavage of hCAP-18)
LL-37 is the C-terminal 37-residue active fragment of the human cathelicidin precursor hCAP-18. It is an endogenous antimicrobial and immunomodulatory peptide expressed by neutrophils, macrophages, and epithelial cells. The peer-reviewed literature is large and includes antimicrobial, anti-HIV, and host-defence research.
Extensive in vitro / animal antimicrobial and immunomodulatory literature; early-phase human studies in skin and infection contexts
Mazdutide (IBI362, originally LY3305677) is a once-weekly dual GLP-1 / glucagon receptor agonist. Originally developed by Eli Lilly and now advanced by Innovent Biologics, mazdutide is most extensively studied in Chinese populations. It has received conditional approval in China for chronic weight management; international regulatory approvals are not yet in place at the time of writing.
Phase III evidence published in Chinese adults with obesity; conditionally approved in China for chronic weight management
Melanotan-1 (afamelanotide) is a synthetic 13-residue analogue of α-melanocyte-stimulating hormone (α-MSH) with substitutions that improve potency and stability. It is FDA-approved as Scenesse (Clinuvel Pharmaceuticals) for the prevention of phototoxicity in adult patients with a history of phototoxic reactions from erythropoietic protoporphyria (EPP).
FDA-approved for erythropoietic protoporphyria (2019); EU approval for EPP earlier; additional research in vitiligo and other photodermatoses
Synthetic cyclic α-MSH analogue · Not approved for human use in any jurisdiction
Melanotan-2 is a synthetic cyclic seven-residue analogue of α-melanocyte-stimulating hormone (α-MSH) that activates multiple melanocortin receptors (notably MC4R). It is not approved as a medicine in any jurisdiction. PT-141 (bremelanotide) was developed from the same cyclic scaffold but is a distinct, separately-approved compound.
Preclinical animal pharmacology; documented adverse-event case reports in unregulated human use
MGF is the E-domain peptide of the IGF-1Ec splice variant. The full-length IGF-1Ec transcript is upregulated in muscle in response to mechanical stress, and synthetic E-domain peptides have been studied for effects on muscle satellite cells, cartilage, and peripheral nerves in rodent and in vitro models.
Mitochondrial-derived peptide (mitochondrial 12S rRNA open reading frame product)
MOTS-c is a 16-residue peptide encoded within the mitochondrial 12S rRNA open reading frame, discovered in 2015. It has been studied in metabolic homeostasis, insulin resistance, and skeletal muscle research. All cited primary studies on this profile are preclinical (mouse and cell models).
Active preclinical literature (mouse and cell models); no controlled human clinical trials at time of writing
Endogenous nonapeptide hormone · FDA-approved (Pitocin) for labour induction and postpartum uterine atony
Oxytocin is an endogenous nine-residue cyclic peptide hormone synthesised in the hypothalamus. It is FDA-approved (Pitocin) for labour induction and management of postpartum uterine atony. Intranasal oxytocin is an active research area in psychiatric and behavioural-neuroscience contexts, though those uses remain investigational.
Decades of obstetric clinical use; active intranasal-pharmacology research in psychiatric and social-behaviour contexts
Shortened spadin analog · TREK-1 channel inhibitor · Preclinical only
PE 22-28 is a shortened analog of spadin (a peptide derived from the propeptide of neurotensin receptor 3 / sortilin) designed by the Mazella / Borsotto group at IPMC-CNRS. It targets the TREK-1 two-pore-domain potassium channel, which has been studied as a depression-associated channel in rodent models.
Khavinson short peptide · Glu-Asp-Arg tripeptide · Preclinical only
Pinealon is a short tripeptide (Glu-Asp-Arg / EDR) developed by the Khavinson research group at the St Petersburg Institute of Bioregulation and Gerontology. Published evidence is preclinical — rodent in vivo and cell-culture studies — and is concentrated within the Khavinson network. There are no FDA, MHRA, or EMA approvals.
Preclinical (rodent and cell-culture) literature from a single research network
Melanocortin receptor agonist · FDA-approved (Vyleesi, as bremelanotide)
PT-141 (bremelanotide) is a cyclic heptapeptide melanocortin receptor agonist derived from α-melanocyte-stimulating hormone (α-MSH). It is FDA-approved as Vyleesi for acquired, generalised hypoactive sexual desire disorder (HSDD) in premenopausal women. Approval is indication-specific.
Phase III clinical evidence; FDA-approved (Vyleesi) for hypoactive sexual desire disorder in premenopausal women
Retatrutide (LY3437943) is a single peptide engineered to act at three incretin and metabolic receptors — GIP, GLP-1, and glucagon. It is investigational and not approved as a medicine at the time of writing. Phase II data have been published for obesity and type 2 diabetes; Phase III trials are ongoing.
Phase II clinical evidence published; Phase III TRIUMPH and TRIUMPH-OUTCOMES programmes ongoing
Selank is a synthetic heptapeptide analogue of the immunopeptide tuftsin, primarily characterised in rodent behavioural models (anxiety, stress, withdrawal) and in vitro neurochemistry assays. Regulatory status varies — research-use context only on this platform.
Rodent behavioural and in vitro neurochemistry literature
Semaglutide is an acylated GLP-1 analogue with a long-chain fatty diacid side chain that extends its half-life via tight albumin binding, enabling once-weekly dosing. It is FDA-approved as Ozempic and Rybelsus (oral) for type 2 diabetes mellitus and as Wegovy for chronic weight management. The STEP programme provides the primary weight-management evidence and the SUSTAIN and SELECT programmes cover diabetes and cardiovascular outcomes.
Phase III clinical evidence; FDA-approved for type 2 diabetes (Ozempic / Rybelsus) and chronic weight management (Wegovy)
Semax is a synthetic heptapeptide derived from ACTH(4–7), most extensively characterised in rodent models of cerebral ischaemia and in vitro neurobiology assays. Approved in the Russian Federation as a research and clinical compound; not approved for human therapeutic use in the United States, United Kingdom, or European Union.
Sermorelin is the C-terminally amidated 29-residue N-terminal fragment of human GHRH. It was FDA-approved as Geref for paediatric growth hormone deficiency in the late 1990s; the originator product was discontinued from US distribution in 2008 and the compound is no longer marketed by the original sponsor. Research literature includes paediatric clinical trials, PEGylated analogue development, and anti-doping detection methodology.
Historical clinical use (paediatric GH deficiency); current research includes preclinical analogue and detection methodology
Cosmetic-research peptide · Acetyl octapeptide-3 · SNARE-complex–targeting analog
SNAP-8 (acetyl octapeptide-3) is a synthetic peptide marketed in cosmetic formulations and studied as a topical agent in small dermatology cohorts. It is an N-acetylated 8-residue analog of the SNAP-25 N-terminus and is proposed to interact with SNARE-complex assembly — a mechanism shared with botulinum-toxin biology, though SNAP-8 itself is not a neurotoxin.
Cosmetic-formulation research — small-cohort human studies and in vitro work
SS-31 (elamipretide, MTP-131) is a mitochondria-targeted synthetic tetrapeptide developed by Szeto and Schiller. It concentrates in the inner mitochondrial membrane and interacts with cardiolipin to support electron transport and reduce reactive oxygen species. It has been studied in multiple late-phase clinical trials (Barth syndrome, primary mitochondrial myopathy, age-related macular degeneration, heart failure) but is not FDA-approved at the time of writing.
Multiple Phase II–III clinical trials (Barth syndrome, primary mitochondrial myopathy, dry AMD, heart failure); not FDA-approved at time of writing
Survodutide (BI 456906) is a once-weekly dual agonist at GLP-1 and glucagon receptors developed by Boehringer Ingelheim. Phase II evidence has been published in adults with obesity and in adults with MASH (metabolic dysfunction-associated steatohepatitis). It is investigational — not FDA-approved at the time of writing.
Phase II clinical evidence published in obesity and metabolic dysfunction-associated steatohepatitis (MASH); Phase III development underway
Tesamorelin is a synthetic 44-residue analogue of human GHRH (with an N-terminal trans-3-hexenoyl modification for stability). It is FDA-approved as Egrifta / Egrifta SV for the reduction of excess abdominal fat in patients with HIV-associated lipodystrophy. Approval is indication-specific; use outside that indication is investigational.
Phase III clinical evidence; FDA-approved for HIV-associated lipodystrophy
Thymalin is a peptide complex extracted from calf thymus tissue, developed and characterised by the Khavinson group in St Petersburg, Russia. It is registered as a preparation in the Russian Federation. The peer-reviewed literature consists predominantly of work from the Khavinson group and collaborators across cellular ageing, immunology, and pineal-thymus axis research.
Khavinson-group experimental and observational literature spanning four decades; limited independent replication outside the originating research network
Synthetic 28-residue immunomodulatory peptide · Approved in multiple jurisdictions (not FDA-approved in the US)
Thymosin Alpha-1 (Tα1, thymalfasin, marketed as Zadaxin) is a synthetic 28-residue immunomodulatory peptide based on a thymic peptide fragment. It is approved in many jurisdictions (including Italy and China) for chronic hepatitis B and as an immunomodulator, and remains unapproved by the FDA in the United States. The most recent Phase III data (Wu 2025, BMJ) examined sepsis.
Phase III clinical evidence including sepsis (BMJ 2025); approved in Italy, China, and other jurisdictions for hepatitis B/C and as an immunomodulator
Thymosin Beta-4 (Tβ4) is a 43-residue actin-binding peptide expressed in many human tissues. Published research spans in vitro cell-biology assays, rodent models, human-organoid work, and a small number of early-phase clinical studies (e.g., in ophthalmology and cardiovascular research).
Cell biology, rodent, and early-phase clinical literature
Tirzepatide is a lipidated synthetic peptide that activates both the GIP and GLP-1 receptors. It is FDA-approved as Mounjaro for type 2 diabetes mellitus and as Zepbound for chronic weight management in adults with obesity or overweight with at least one weight-related condition. The SURPASS (T2D) and SURMOUNT (obesity) Phase III trial programmes provide the primary efficacy and safety evidence base.
Phase III clinical evidence; FDA-approved for type 2 diabetes (Mounjaro) and chronic weight management (Zepbound)
VIP is an endogenous 28-residue neuropeptide discovered in the 1970s. It functions as a neurotransmitter, vasodilator, and immunomodulator. Most published research is mechanistic (cell biology, animal physiology) or focused on VIP-secreting tumours (VIPomas); a smaller body of clinical research has explored VIP and its analogues in pulmonary, inflammatory, and cancer-targeting contexts.
Extensive endogenous-physiology and pathophysiology literature; small clinical trials in pulmonary and inflammatory disease
