Peptide Directory

A GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management, one of the most widely prescribed peptide drugs.

A dual GIP/GLP-1 receptor agonist FDA-approved for diabetes and weight management, producing the largest weight loss seen in clinical trials.

Recombinant human growth hormone — the full 191-amino-acid pituitary peptide, FDA-approved for a short list of specific deficiency and wasting indications and the subject of an enormous off-label market for anti-aging, performance, and body-composition use that runs far ahead of the evidence.

The 51-amino-acid two-chain pancreatic hormone discovered by Banting, Best, Macleod, and Collip at the University of Toronto in 1921-22 — the first life-saving peptide drug, the molecule whose primary structure Frederick Sanger determined in 1955 (the first protein ever sequenced), and the cornerstone of type 1 diabetes management plus advanced type 2 diabetes care for over a century.

An investigational triple agonist (GIP/GLP-1/glucagon) from Eli Lilly. Not FDA-approved. Phase III TRIUMPH-4 results showed 23.7% weight loss — the most of any obesity drug in development.

A naturally occurring neuropeptide involved in social bonding, trust, and reproduction, FDA-approved for labor induction.

A 165-amino-acid glycoprotein hormone produced by the kidney that drives red blood cell production. FDA-approved as recombinant human EPO and longer-acting analogs for anemia of chronic kidney disease, chemotherapy, and HIV — and infamous as an endurance-sports doping agent prohibited at all times by WADA.

A growth hormone-releasing hormone analog that was previously FDA-approved for diagnosing GH deficiency in children.

An FDA-approved melanocortin receptor agonist for hypoactive sexual desire disorder in premenopausal women, also studied for broader sexual dysfunction.

A GLP-1 receptor agonist FDA-approved for diabetes (Victoza) and weight management (Saxenda), the predecessor to semaglutide.

A long-acting amylin analogue being developed in combination with semaglutide (CagriSema) for enhanced weight loss.

A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes, with proven cardiovascular benefits and moderate weight loss effects.

Foundayo (orforglipron) is Eli Lilly's oral small-molecule GLP-1 receptor agonist. Phase 3 trials show up to 11.2% weight loss via daily pill — no injections required. Regulatory submissions expected 2026.

An investigational dual glucagon/GLP-1 receptor agonist from Boehringer Ingelheim and Zealand Pharma. Phase 3 SYNCHRONIZE-1 (April 28, 2026 topline) achieved 16.6% mean weight loss at 76 weeks — the first positive Phase 3 readout in the SYNCHRONIZE obesity program. FDA Fast Track (2021) and Breakthrough Therapy (2024) designations for MASH; full SYNCHRONIZE-1 data at ADA June 2026.

The 167-amino-acid adipose hormone discovered in 1994 that was supposed to cure obesity — and did, for the handful of people born without it. For everyone else, the story turned out to be leptin resistance, not leptin deficiency, and the therapeutic lesson has been much harder than the biology.

Novo Nordisk's investigational unimolecular dual GLP-1 and amylin receptor agonist, advanced in both subcutaneous and oral formulations. Phase 1b/2a SC topline (Lancet 2025) showed up to 24.3% mean weight loss at 36 weeks — among the largest weight-loss signals reported for any single peptide, anywhere. Not approved by any regulator; Phase 2 obesity program underway.

An FDA-approved GHRH analog used to reduce visceral fat in HIV-associated lipodystrophy.

Synthetic gonadotropin-releasing hormone used diagnostically and therapeutically for reproductive hormone assessment and fertility.

Amgen's first-in-class once-monthly bispecific antibody-peptide conjugate for obesity — GLP-1 receptor agonist + GIP receptor antagonist. Phase 2 NEJM showed up to 21.6% weight loss at 52 weeks with no plateau.

The endogenous 28-amino-acid 'hunger hormone' from the stomach — the natural ligand of GHS-R1a, the receptor that GHRP-2, GHRP-6, hexarelin, ipamorelin, and MK-677 all target. A research peptide and pharmacology reference, not a self-administered compound.

The TGF-β superfamily protein that negatively regulates skeletal muscle mass — the biological target behind 'mighty mice,' Belgian Blue cattle, and an entire class of investigational inhibitor drugs that have underdelivered on the hype.

The endogenous 13-amino-acid melanocortin hormone cleaved from POMC. Parent molecule for the melanotan / setmelanotide / KPV cluster — acts at MC1R (pigmentation), MC3R/MC4R (appetite, energy balance), and MC5R, with well-characterized anti-inflammatory activity.

An endogenous gut-and-brain peptide hormone released by intestinal I-cells that triggers gallbladder contraction, pancreatic enzyme secretion, and meal-ending satiety via vagal CCK-1 receptors.

An FDA-approved 14-amino-acid oral peptide that activates intestinal guanylate cyclase-C to treat chronic idiopathic constipation and IBS-C in adults, plus functional constipation in children 6-17.

The circulating 'cellular stress' hormone of the TGF-β superfamily — the molecule that links metformin-induced weight loss, pregnancy-associated hyperemesis, and cancer cachexia through a single brainstem receptor (GFRAL). Not a self-administered peptide; the clinical programs are antibodies that block GDF-15, not supply it.

The endogenous 8-amino-acid effector peptide of the renin-angiotensin-aldosterone system (RAAS) — the body's master vasoconstrictor and aldosterone-release signal, and, as synthetic Giapreza, an FDA-approved IV infusion for catecholamine-resistant vasodilatory shock.

A growth hormone-releasing hormone analog that stimulates the pituitary gland to produce more growth hormone.

Precursors to NAD+, a critical coenzyme for cellular energy and longevity pathways. NAD+ levels decline with age.

The most-studied copper peptide in skincare — a naturally occurring tripeptide (GHK, Gly-His-Lys) whose active tissue form is the copper complex GHK-Cu, with extensive evidence for skin remodeling, collagen synthesis, wound healing, and anti-aging.

The body's most abundant antioxidant — a tripeptide critical for detoxification, immune function, and cellular protection, and one of the most widely used systemic skin-brightening and hyperpigmentation interventions via oral, IV, SubQ/IM, and topical routes (note: IV use for skin lightening is FDA-flagged and not approved).

An orally active growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release.

A modified growth hormone releasing hormone analog with a shorter half-life than DAC-conjugated CJC-1295, allowing more physiological GH pulsing.

A cosmetic peptide that reduces wrinkles by inhibiting neurotransmitter release at the neuromuscular junction, often called 'topical Botox.'

The active isomer of clomiphene, a selective estrogen receptor modulator (SERM) that raises testosterone while preserving fertility. Not FDA-approved as a standalone drug, but widely available through compounding pharmacies.

The hepatic peptide hormone of fasting and ketogenic states — and the target behind the most exciting current NASH/MASH pipeline. Native FGF21 has a half-life measured in hours; the clinical drugs are engineered Fc-fusions and PEGylated variants dosed weekly.

Placental glycoprotein hormone that acts as an LH-receptor agonist — used clinically as an ovulation trigger in IVF and off-label in men to stimulate endogenous testosterone and preserve fertility during or after exogenous androgen use.

A porcine brain-derived peptide preparation with neurotrophic properties, approved in several countries for stroke recovery and cognitive disorders.

A potent growth hormone secretagogue peptide that also has cardioprotective properties independent of GH release.

A biased-agonist GLP-1 receptor agonist from Sciwind Biosciences, engineered to favor Gs/cAMP signaling over β-arrestin recruitment. Phase 3 data in overweight/obese adults showed ~13.2% body weight reduction at 40 weeks. Approved or pending approval in China; not FDA-approved.

An endogenous 36-amino-acid gut hormone released by intestinal L-cells after meals; its active fragment PYY(3-36) is a Y2-receptor-selective satiety signal.

A urine-derived gonadotropin preparation containing both FSH and LH activity, used for ovulation induction and controlled ovarian stimulation in IVF — the original injectable fertility drug, still in use as Menopur and HP-hMG formulations.

A thymic peptide approved in multiple countries for immune modulation, particularly in hepatitis and as a vaccine adjuvant.

A synthetic peptide that regulates intestinal tight junctions, in clinical trials for celiac disease and studied for leaky gut conditions.

The first GLP-1 receptor agonist, originally derived from Gila monster venom, FDA-approved for type 2 diabetes.

An FDA-approved fragment of parathyroid hormone that stimulates new bone formation, used for severe osteoporosis.

An FDA-approved GnRH agonist used for prostate cancer, endometriosis, and precocious puberty through hormonal suppression.

A naturally occurring peptide hormone that raises blood sugar, FDA-approved as emergency treatment for severe hypoglycemia.

A triple monoamine reuptake inhibitor (serotonin, noradrenaline, dopamine) that produced up to 10.6% weight loss in Phase 2 trials — roughly double the efficacy of older appetite suppressants. Approved in Mexico; not yet FDA-approved.

The world's first approved dual GLP-1/glucagon receptor agonist, developed by Innovent Biologics (China). Approved in China for obesity and type 2 diabetes. Phase 3 trials showed up to 20.1% weight loss.

Zealand Pharma's long-acting amylin analog, partnered with Roche in a $5.3B deal. Phase 2b ZUPREME-1 showed 10.7% weight loss at 42 weeks with placebo-like tolerability — the 'tolerability play' in the amylin class.

Roche/Genentech's next-generation dual GLP-1/GIP receptor agonist (INN: enicepatide, assigned 2026). Phase 2 showed 22.5% placebo-adjusted weight loss at 48 weeks — competitive with retatrutide. Phase 3 ENITH program initiated Q1 2026 with two pivotal trials.

The first FDA-approved mitochondria-targeted peptide. Stealth BioTherapeutics received accelerated approval in September 19, 2025 for Barth syndrome — a rare X-linked cardiolipin disorder affecting roughly 150 people in the US — marketed as Forzinity.

A modified C-type natriuretic peptide analog developed by BioMarin Pharmaceutical, FDA-approved as Voxzogo for children with achondroplasia. The first targeted pharmacological treatment for the most common form of genetic short stature.

An FDA-approved synthetic analog of parathyroid hormone-related protein (PTHrP 1-34) used to stimulate new bone formation in postmenopausal women at high risk of fracture.

The endogenous nine-amino-acid posterior-pituitary hormone that regulates water balance, vascular tone, and the stress axis — FDA-approved for central diabetes insipidus and vasodilatory shock.

The endogenous cyclic neuropeptide (SST-14 and SST-28 isoforms) that acts as the body's universal inhibitor of hormone and exocrine secretion — the physiological parent of the approved analogs octreotide, lanreotide, and pasireotide.

The native hypothalamic decapeptide that sits at the top of the reproductive axis, releasing LH and FSH in pulses to drive gonadal steroidogenesis.

The 244-amino-acid adipocyte-secreted hormone discovered independently by four groups in 1995–1996 — unusual among adipokines in that its levels fall with obesity, not rise with it. High-adiponectin states are protective; low-adiponectin states track insulin resistance, type 2 diabetes, and cardiovascular disease. Direct therapeutic use is limited by its large multimeric structure, and the field's forward push is toward small-molecule AdipoR agonists like AdipoRon.

A 36-amino-acid endogenous neuropeptide, one of the most abundant in the mammalian brain and the central nervous system's primary orexigenic (hunger-driving) signal.

An 11-amino-acid endogenous tachykinin neuropeptide encoded by the TAC1 gene that acts primarily at the neurokinin-1 (NK1) receptor — the first identified peptide neurotransmitter and a central mediator of pain transmission, neurogenic inflammation, and the vomiting reflex.

The 31-amino-acid endogenous opioid peptide cleaved from POMC in the pituitary and hypothalamus. The canonical 'endorphin' of popular science — invoked to explain runner's high, placebo analgesia, and acupuncture — though modern evidence has substantially weakened the classical runner's-high story.

A 27-amino-acid peptide hormone produced by S cells of the duodenal mucosa — historically the first hormone ever identified (Bayliss & Starling, 1902, who coined the word 'hormone' to describe it). Secretin stimulates pancreatic bicarbonate-rich fluid secretion, modulates gastric acid via somatostatin, and is FDA-approved as a synthetic diagnostic reagent (ChiRhoStim) for pancreatic-function testing, gastrinoma evaluation, and secretin-stimulated MRCP imaging.

An FDA-approved selective MC1R agonist for erythropoietic protoporphyria (EPP). Stimulates protective eumelanin production without the broad side effects of Melanotan II.

An FDA-approved peptide hormone used to treat osteoporosis and Paget's disease by inhibiting bone resorption.

A synthetic analogue of vasopressin (ADH) FDA-approved for diabetes insipidus, bedwetting, and bleeding disorders.

An FDA-approved synthetic analogue of amylin used alongside insulin for diabetes, also studied for weight management.

An FDA-approved MC4R agonist for rare monogenic obesity (POMC/PCSK1/LEPR deficiency, Bardet-Biedl syndrome) and — as of March 2026 — acquired hypothalamic obesity in patients aged 4 and older.

An FDA-approved somatostatin analogue used to treat acromegaly, carcinoid tumors, and severe diarrhea.

An FDA-approved immunomodulatory peptide mixture for relapsing-remitting multiple sclerosis (MS).

An FDA-approved GnRH agonist used for prostate cancer, endometriosis, central precocious puberty, and discussed in the peptide community for post-cycle hormonal resets.

The pituitary hormone that tells the adrenal gland to make cortisol — available as the synthetic 1-24 fragment (cosyntropin) for adrenal testing and as a long-acting gel (Acthar) for a handful of inflammatory indications.

The endogenous 33-amino-acid intestinotrophic hormone co-released with GLP-1 from intestinal L-cells — the physiological template behind the FDA-approved short bowel syndrome drug teduglutide.

An FDA-approved long-acting somatostatin analog used to treat acromegaly, gastroenteropancreatic neuroendocrine tumors, and carcinoid syndrome.

An FDA-approved GnRH receptor antagonist decapeptide used for advanced prostate cancer — suppresses testosterone within days with no initial flare, in contrast to GnRH agonists like leuprolide and triptorelin.

A 132-amino-acid endogenous neuropeptide (processed to the ~83 aa C-terminal active form) expressed almost exclusively in a discrete population of arcuate-nucleus neurons. Acts as an inverse agonist and competitive antagonist at MC3R and MC4R — the counter-regulatory signal to α-MSH in the leptin–melanocortin appetite circuit and the defining 'hunger neuron' marker.

An FDA-approved synthetic prostaglandin E1 (PGE1) — a 20-carbon eicosanoid lipid, not a peptide — used as an intracavernosal injection, urethral suppository, or topical cream for erectile dysfunction, and as an intravenous infusion in neonates to maintain ductus arteriosus patency in ductus-dependent congenital heart disease.

FDA-approved erythroid maturation agent — a modified ActRIIB-IgG1-Fc ligand trap that binds GDF11, activin B, and related TGF-β superfamily ligands to relieve Smad2/3-driven block on late-stage erythropoiesis. Approved for transfusion-dependent β-thalassemia (BELIEVE) and lower-risk myelodysplastic syndromes (MEDALIST, COMMANDS).

FDA-approved (March 2024) first-in-class activin signaling inhibitor for pulmonary arterial hypertension — a recombinant ActRIIA-IgG1-Fc fusion that traps activin A and related TGF-β superfamily ligands to rebalance pro-proliferative and anti-proliferative signaling in the pulmonary vasculature. Pivotal evidence: PULSAR (NEJM 2021), STELLAR (NEJM 2023), ZENITH (NEJM 2025).

Orally active ghrelin receptor agonist, FDA-approved in 2017 as a single-dose diagnostic for adult growth hormone deficiency — not a treatment.

An endogenous 29-amino-acid (30 in humans) neuropeptide discovered in 1983 by Tatemoto, signaling through three G-protein-coupled receptor subtypes (GAL1, GAL2, GAL3) and modulating feeding, mood, nociception, seizure activity, and basal-forebrain cholinergic neurodegeneration in Alzheimer's disease.

An endogenous 21-amino-acid peptide produced by vascular endothelial cells, isolated and sequenced in 1988 by Masashi Yanagisawa and colleagues at Tsukuba — the most potent vasoconstrictor known in mammalian biology, signaling through ETA and ETB G-protein-coupled receptors and the molecular target of the FDA-approved endothelin receptor antagonist (ERA) drug class used to treat pulmonary arterial hypertension and resistant hypertension.

A family of endogenous opioid peptides derived from the prodynorphin (PDYN) gene that are selective agonists at the kappa-opioid receptor (KOR), best known as the dysphoric, aversive, stress-induced counterpart to the euphoric mu-receptor-preferring beta-endorphin system, and the biological target of the new generation of KOR-antagonist antidepressants (aticaprant, navacaprant).

An endogenous 13-amino-acid neuropeptide isolated from bovine hypothalamus by Robert Carraway and Susan Leeman in 1973, signaling through three receptors (NTS1, NTS2, and the sortilin/NTS3 sorting receptor) and modulating dopaminergic transmission, gastrointestinal motility, thermoregulation, blood pressure, and analgesia — with major translational interest in NTS1 agonists for schizophrenia and NTS1-targeted radioligand therapy in cancer.

A 22-amino-acid gut hormone produced by M cells of the proximal small-intestinal mucosa, isolated and named by John Christopher Brown's group in Vancouver between 1966 and 1971, signaling through a single G-protein-coupled receptor (MLNR/GPR38) to drive the gastric phase III of the migrating motor complex during fasting.

An endogenous peptide hormone discovered functionally by John Edkins in 1905 and structurally solved by Roderic Gregory and Hilda Tracy at Liverpool in 1964. Produced by G cells of the gastric antrum and duodenum, secreted in two principal molecular forms (G17 and G34) sharing the C-terminal Trp-Met-Asp-Phe-NH2 pharmacophore with cholecystokinin, and acting at the CCK-2/CCK-B receptor to drive parietal-cell acid secretion via ECL-cell histamine release and to exert trophic effects on the oxyntic mucosa.

An endogenous 7-amino-acid peptide (Asp-Arg-Val-Tyr-Ile-His-Pro) generated principally from angiotensin II by ACE2, acting at the Mas receptor as the counter-regulatory arm of the renin-angiotensin-aldosterone system — opposing angiotensin II's vasoconstriction, fibrosis, and pressor effects with vasodilatory, anti-fibrotic, and cardioprotective signaling.

A 36-amino-acid hormone of the PP-fold family produced by the F-cells (PP-cells) of the pancreatic islets, isolated by James Kimmel at the University of Kansas in 1975 and characterized as a postprandial vagally-mediated anorectic hormone that signals preferentially through the Y4 receptor — together with peptide YY and neuropeptide Y, it forms the canonical PP-fold/NPY family of feeding-related peptides.

A semi-synthetic polysaccharide with FDA approval for interstitial cystitis, also studied for joint and cartilage health.

An FDA-approved peripheral kappa opioid receptor agonist for chronic kidney disease-associated itch, without CNS side effects.

An FDA-approved GLP-2 analogue that promotes intestinal growth, used for short bowel syndrome.

The first FDA-approved treatment for Rett syndrome, a synthetic analogue of a naturally occurring IGF-1 tripeptide fragment.

An FDA-approved pan-somatostatin analog (SSTR1/2/3/5) used as first-line medical therapy for Cushing's disease and second-line for acromegaly.

An FDA-approved GnRH agonist delivered intranasally — the only GnRH agonist in routine US nasal-spray practice — used for endometriosis and central precocious puberty.

An FDA-approved GnRH agonist nonapeptide delivered via a once-yearly subcutaneous hydrogel implant, used for central precocious puberty (Supprelin LA) and historically for advanced prostate cancer (Vantas).

An FDA-approved synthetic decapeptide that selectively antagonizes the bradykinin B2 receptor, used as on-demand subcutaneous treatment for acute attacks of hereditary angioedema (HAE) in adults.

An endogenous gonadal dimeric protein hormone (TGF-β superfamily) that selectively suppresses pituitary FSH secretion and is used clinically as a biomarker for fertility, granulosa cell tumors, and prenatal screening.

An FDA-approved synthetic 20-amino-acid direct thrombin inhibitor used as an intravenous anticoagulant during percutaneous coronary intervention (PCI) and as a non-heparin option in patients with heparin-induced thrombocytopenia.

An FDA-approved synthetic cyclic heptapeptide glycoprotein IIb/IIIa receptor antagonist used as an intravenous antiplatelet agent during percutaneous coronary intervention and acute coronary syndromes, derived from the KGD motif of barbourin in southeastern pygmy rattlesnake venom.

An endogenous 32-amino-acid cardiac hormone secreted primarily by ventricular myocytes in response to wall stretch — the dominant natriuretic peptide in clinical practice and the basis of the BNP and NT-proBNP assays used worldwide for heart failure diagnosis, risk stratification, and management.

FDA-approved thrombopoietin-receptor agonist peptibody — four identical 14-amino-acid TPO-mimetic peptides covalently fused to a human IgG1 Fc scaffold — administered as a weekly subcutaneous injection for chronic immune thrombocytopenia (FDA 2008) and acute radiation syndrome (FDA 2021). The first-in-class peptibody.

An endogenous 52-amino-acid vasodilator peptide of the CGRP/calcitonin family, isolated in 1993 by Kitamura and colleagues from human pheochromocytoma tissue, signaling through the calcitonin-receptor-like receptor (CLR) coupled with RAMP2 or RAMP3 to regulate vascular tone, endothelial barrier integrity, and cardio-renal physiology — and the source of two clinically meaningful therapeutic angles: MR-proADM as a sepsis and cardiovascular biomarker, and the anti-AM monoclonal antibody enibarcimab (formerly adrecizumab) as an investigational sepsis therapeutic.

An endogenous 22-amino-acid peptide identified in 1990 by Sudoh, Minamino, Kangawa, and Matsuo as the third member of the natriuretic peptide family. Unlike ANP and BNP, CNP is predominantly endothelial and chondrocytic rather than cardiac, signals through NPR-B (not NPR-A), and is the master driver of endochondral long-bone growth — the biology that vosoritide (Voxzogo) was engineered to mimic for achondroplasia.

A 19-amino-acid cyclic neuropeptide originally discovered in 1983 by Kawauchi and colleagues in chum salmon pituitary for its skin-pallor-inducing effect, and later identified as a potent orexigenic signal in mammals — released by lateral hypothalamic neurons, signaling primarily through MCH-R1 (a functional MCH-R2 exists in primates and dogs but is a pseudogene in rodents), and a long-running but unsuccessful obesity drug-discovery target.

An FDA-approved synthetic 25-amino-acid peptide derived from the venom of the marine cone snail Conus magus that selectively blocks N-type voltage-gated calcium channels in spinal cord nociceptive pathways. Delivered intrathecally via implanted pump for severe, refractory chronic pain — non-opioid, non-tolerizing, but constrained by a famously narrow therapeutic window and prominent neuropsychiatric side effects.

An FDA-approved synthetic 36-amino-acid peptide derived from the HR2 region of HIV-1 gp41. Enfuvirtide is the first-in-class HIV fusion inhibitor, given as a twice-daily subcutaneous injection in heavily treatment-experienced patients with multidrug-resistant HIV-1.

A once-weekly long-acting GLP-1 receptor agonist developed by GlaxoSmithKline as a recombinant fusion of two tandem GLP-1(7-36) sequences with human serum albumin — FDA-approved as Tanzeum (US) and Eperzan (EU) in 2014 for type 2 diabetes, achieved a positive cardiovascular outcomes signal in HARMONY OUTCOMES (Lancet 2018), but commercially withdrawn by GSK in 2017 due to weak market uptake against semaglutide and liraglutide.

A synthetic peptide derived from a protective protein found in gastric juice, widely discussed for tissue repair and recovery.

A selective growth hormone secretagogue that stimulates GH release without significantly affecting cortisol or prolactin.

A synthetic version of the active region of thymosin beta-4, widely used for tissue repair, wound healing, and recovery from injuries.

A synthetic peptide analog of ACTH(4-10) developed in Russia, studied for cognitive enhancement and neuroprotection.

A naturally occurring protein that inhibits myostatin (the muscle growth limiter), studied for dramatic muscle growth potential.

A tripeptide fragment of alpha-MSH with potent anti-inflammatory properties, studied for inflammatory bowel disease and skin conditions.

A collagen-stimulating cosmetic peptide that signals skin to produce more collagen and extracellular matrix proteins.

The longevity protein discovered in 1997 as a mouse-aging-syndrome gene, now the subject of rigorous cognitive-aging research (the KL-VS variant confers real cognitive protection) and a grey-market 'Klotho peptide' industry that oversells early-stage academic work.

A synthetic peptide analog of tuftsin with anxiolytic and nootropic properties, developed in Russia.

A modified fragment of human growth hormone studied specifically for fat metabolism without the growth-promoting effects of full GH.

A synthetic growth hormone secretagogue that stimulates natural GH release, studied for body composition, recovery, and anti-aging.

A modified version of IGF-1 with extended half-life and reduced IGF binding protein affinity, used for muscle growth.

An enhanced version of Selank with improved stability, studied for anxiety reduction and cognitive enhancement.

A naturally occurring dipeptide concentrated in muscle and brain tissue, studied for anti-aging, cognitive support, and exercise performance.

A collagen-boosting cosmetic peptide that mimics the body's wound-healing signal to stimulate collagen and elastin production in the skin.

An endogenous 37-amino-acid gut hormone and natural dual agonist at the GLP-1 and glucagon receptors — the physiologic template behind the dual-agonist obesity drug class (cotadutide, survodutide, mazdutide).

A naturally occurring neuropeptide with anti-inflammatory, neuroprotective, and immune-modulating properties. Early clinical data exists for pulmonary hypertension; other therapeutic uses remain under investigation.

A synthetic growth hormone secretagogue known for potent GH release and significant appetite stimulation through ghrelin receptor activation.

An investigational once-weekly dual GLP-1/GIP receptor agonist from Jiangsu Hengrui, with ex-Greater China rights held by Kailera Therapeutics. Phase 3 in China produced up to 19.2% weight loss at 48 weeks; a global Phase 3 (KaiNETIC) began enrolling in January 2026.

Eli Lilly's once-weekly selective amylin receptor agonist. Phase 2 trials showed up to 20% weight loss at 48 weeks with favorable tolerability. Phase 3 enrollment began late 2025.

Pfizer's ultra-long-acting, fully-biased GLP-1 receptor agonist designed for once-monthly injection — with 12.3% placebo-adjusted weight loss at 28 weeks in Phase 2b and a 10-trial Phase 3 program planned.

A thymic peptide complex studied for immune system restoration, particularly in aging populations and immunocompromised states.

A skin-brightening peptide that inhibits tyrosinase up to 17x more potently than hydroquinone, used for hyperpigmentation, melasma, and uneven skin tone.

The original 'exercise in a pill' — an AMPK activator that increased running endurance by 44% in sedentary mice. Banned by WADA since 2009. Studied for metabolic syndrome, diabetes, and cardioprotection.

Acceleron Pharma's soluble ActRIIB-Fc decoy receptor — a myostatin/activin ligand trap that produced striking muscle-mass signals in healthy volunteers and Duchenne boys before its Phase 2 DMD program was halted in 2011 over epistaxis and telangiectasia attributed to broad TGF-β pathway blockade.

A 25-amino-acid antimicrobial peptide secreted by the liver that serves as the master hormone of systemic iron homeostasis. By binding and internalizing the iron-efflux transporter ferroportin, hepcidin restricts iron release from enterocytes and macrophages into the circulation — and is central to the pathophysiology of anemia of inflammation, hereditary hemochromatosis, and polycythemia vera.

An endogenous 9-amino-acid vasoactive peptide generated by kallikrein cleavage of kininogen; the primary effector of the kinin-kallikrein system, driving vasodilation, vascular permeability, pain, and the molecular basis of hereditary angioedema and ACE-inhibitor cough.

An FDA-approved first-in-class reversible proteasome inhibitor — a dipeptide boronic acid — that defined modern multiple myeloma therapy and the peptide-boronate drug class.

An endogenous 28-amino-acid cardiac hormone secreted by atrial myocytes in response to wall stretch; drives natriuresis, vasodilation, and renin-aldosterone suppression. Approved in Japan as carperitide (recombinant human ANP) for acute decompensated heart failure since 1995, but never FDA-approved in the United States.

A 9-amino-acid cyclic tumor-homing peptide (Lisata Therapeutics) derived from Erkki Ruoslahti's iRGD platform that activates the CendR (C-end Rule) tumor-penetration pathway — binding αv-integrins on tumor vasculature, undergoing neuropilin-1-mediated cleavage, and enabling enhanced delivery of co-administered chemotherapy into otherwise-impermeable tumor tissue. Active Phase 2/3 development in pancreatic ductal adenocarcinoma (with gemcitabine + nab-paclitaxel) and Phase 2a in glioblastoma.

A naturally occurring neuropeptide that plays a central role in reproductive hormone regulation and fertility.

A mitochondria-targeted cardiolipin-stabilizing tetrapeptide FDA-approved in September 2025 as Forzinity for Barth syndrome — the first approved mitochondria-targeted peptide — with ongoing trials in dry AMD, mitochondrial myopathy, and heart failure.

A short-acting GLP-1 receptor agonist originally approved for type 2 diabetes, now studied for slowing motor decline in early Parkinson's disease.

A GnRH agonist nonapeptide approved in Europe and Canada since the 1980s for prostate cancer, endometriosis, fibroids, IVF, and precocious puberty — but never FDA-approved in the US.

An insulin-superfamily peptide hormone best known for softening pelvic ligaments and the cervix before childbirth, later developed as the failed heart-failure drug serelaxin.

An endogenous peptide hormone and ligand of the APJ receptor with positive inotropic, vasodilatory, and insulin-sensitizing effects — heavily studied as a heart-failure target but not available as an approved therapy, with small-molecule APJ agonists now advancing through early clinical trials.

The smallest hypothalamic releasing hormone — a tripeptide that drives TSH and prolactin secretion and was the first hypothalamic factor to be isolated and sequenced, earning Guillemin and Schally the 1977 Nobel Prize.

An FDA-approved second-generation, irreversible epoxyketone proteasome inhibitor — derived from the natural product epoxomicin — used intravenously in relapsed and refractory multiple myeloma.

A family of three corticotropin-releasing-factor-related neuropeptides — urocortin 1 (Vaughan and Vale, 1995), urocortin 2 (stresscopin-related peptide), and urocortin 3 (stresscopin) — that signal through CRH receptor types 1 and 2 to modulate the stress axis, cardiovascular function (potent inotropic and vasodilator effects in heart failure), appetite, and anxiety.

An 82-amino-acid anorexigenic peptide derived from N-terminal cleavage of the nucleobindin-2 (NUCB2) precursor, identified in 2006 by Oh-I, Shimizu, Mori and colleagues at Gunma University in a Nature paper as a satiety molecule that suppresses food intake through a leptin-independent hypothalamic-melanocortin pathway, with additional documented roles in glucose homeostasis, cardiovascular regulation, and stress responses — receptor unidentified.

An endogenous tetrapeptide (Tyr-Pro-Trp-Phe-NH2) discovered by James Zadina at Tulane in 1997 that is the most selective and potent natural agonist of the mu-opioid receptor identified to date — pharmacologically extraordinary, structurally unrelated to the YGGFL enkephalin family, and central to ongoing efforts to design opioid analgesics with reduced respiratory depression and abuse liability.

An endogenous somatostatin-family neuropeptide identified in 1996 by Luis de Lecea and J. Gregor Sutcliffe at the Scripps Research Institute, expressed in cortical and hippocampal GABAergic interneurons and signaling through all five somatostatin receptors plus the ghrelin receptor and a separate cortistatin-preferring binding site, with distinctive roles in slow-wave sleep, neuronal depression, and immune anti-inflammatory regulation that distinguish it from somatostatin despite extensive pharmacological overlap.

An endogenous neuropeptide isolated from porcine spinal cord by Naoto Minamino, Kenji Kangawa, and Hisayuki Matsuo at the National Cardiovascular Center in Osaka in 1985, named for its uterus-stimulating activity but now best characterized as an anorectic feeding-suppressing neuropeptide acting at NMUR1 (peripheral) and NMUR2 (central, brain-enriched) receptors with additional roles in circadian rhythm, stress, immunity, and Th2 inflammation.

An endogenous analgesic dipeptide (L-tyrosyl-L-arginine) discovered in 1979 by Hiroshi Takagi's group at Kyoto University and named for the city, producing morphine-like analgesia in rodent models through a Met-enkephalin-releasing mechanism rather than direct opioid receptor binding — one of the smallest endogenous neuropeptides and an enduringly studied alternative-analgesic candidate.

An endogenous 20-amino-acid neuropeptide named for its highly conserved N-terminal serine residue, discovered by Xu, Reinscheid, and Civelli at UC Irvine in 2004 by reverse-pharmacology deorphanization of GPR154 (now NPSR1) — pharmacologically distinctive for producing simultaneous wakefulness/arousal AND anxiolytic effects, a combination that classical anxiolytics do not deliver, and the molecular substrate for the natural-short-sleeper NPSR1 mutation identified in human pedigrees.

An endogenous human five-amino-acid peptide (Gln-Arg-Phe-Ser-Arg) discovered in 2006 by Catherine Rougeot and colleagues at the Institut Pasteur — a dual ectopeptidase inhibitor that simultaneously blocks neutral endopeptidase (neprilysin) and aminopeptidase N to prevent enkephalin degradation, thereby potentiating endogenous mu/delta-opioid signaling. Reported as a non-addictive endogenous analgesic with morphine-comparable potency in rodent models, with stabilized analogs (STR-324) advancing toward clinical pain indications.

A family of opioid-active peptides released by gastrointestinal digestion of bovine beta-casein, isolated by Brantl, Henschen, Teschemacher, and colleagues at the Max-Planck-Institut für Psychiatrie in 1979 — the seven-residue beta-casomorphin-7 (BCM-7) is the most studied member, central to the long-running A1 versus A2 milk debate, and the canonical example of an exogenous food-derived (exorphin) opioid peptide.

An 11-amino-acid peptide engineered from erythropoietin that retains tissue-protective effects without raising red blood cell count. Studied for neuropathic pain, small fiber neuropathy, and tissue repair.

A 17-amino-acid endogenous neuropeptide discovered in 1995 as the natural ligand of the orphan opioid-like receptor (now the NOP receptor), cleaved from the same prepronociceptin precursor as nocistatin but with functionally opposing pain pharmacology.

An FDA-approved (August 2001) recombinant human B-type natriuretic peptide given as an IV bolus and infusion for short-term symptom relief in acute decompensated heart failure. After the 2005 Sackner-Bernstein safety controversy and the largely neutral 2011 ASCEND-HF trial, nesiritide use collapsed and the drug is now rarely used in contemporary practice despite remaining nominally on-market.

An endogenous tetrapeptide (Thr-Lys-Pro-Arg) cleaved from residues 289-292 of the IgG heavy chain Fc region, discovered and named at Tufts University in 1970 by Najjar and Nishioka, and best characterized as a stimulator of macrophage and neutrophil phagocytosis, chemotaxis, and antimicrobial activity.

A recently discovered (Yosten, Lyu, Hsueh, Samson 2013) endogenous neuropeptide derived from the small integral membrane protein 20 (SMIM20) precursor — biologically active in two forms (PNX-14 and PNX-20), signaling through the orphan receptor GPR173, and characterized as a positive regulator of GnRH/kisspeptin reproductive signaling with additional documented roles in anxiety, memory, cardiovascular function, food intake, and thirst.

A cationic antimicrobial peptide derived from N-terminal proteolytic cleavage of lactoferrin (the iron-binding glycoprotein abundant in milk, saliva, tears, and neutrophil granules) — bovine lactoferricin (Lfcin-B, residues 17-41) is a 25-amino-acid amphipathic peptide identified by Bellamy and colleagues in 1992 as the bactericidal core of lactoferrin, with broad-spectrum activity against Gram-positive and Gram-negative bacteria, fungi, viruses, and parasites, plus apoptosis-inducing activity in tumor cell lines.

A 10-amino-acid mammalian member of the bombesin peptide family, isolated from porcine spinal cord by Naoto Minamino, Kenji Kangawa, and Hisayuki Matsuo at the National Cardiovascular Center in Osaka in 1983 — the same laboratory that produced ANP, BNP, NMU, and ghrelin. NMB signals through the bombesin receptor subtype 1 (NMBR / BB1), distinct from the GRP-preferring BB2 (GRPR), with documented roles in smooth-muscle contraction, thyroid TSH regulation, satiety, anxiety, thermoregulation, and pain/itch processing.

A stabilized form of BPC-157 combined with arginine, offering enhanced stability and potentially improved oral bioavailability.

A 12-amino-acid peptide cleaved from the BRINP2 protein that activates hypothalamic POMC neurons via a non-incretin pathway. Identified by Stanford's Svensson lab using AI-driven prohormone-cleavage prediction and published in Nature (2025). Preclinical only — no human trials have been initiated as of April 2026.

A senolytic peptide designed to selectively clear senescent cells by disrupting the FOXO4-p53 interaction, studied for anti-aging applications.

A synthetic melanocortin peptide studied for tanning, sexual function, and appetite suppression. Not FDA-approved; the FDA has issued public warnings against its use.

A synthetic tetrapeptide studied for its potential to activate telomerase and influence cellular aging.

A mitochondria-derived peptide with cytoprotective properties, studied for neuroprotection, metabolic regulation, and anti-aging effects.

A truncated form of IGF-1 missing the first 3 amino acids, with 10x greater potency and very short half-life for localized effects.

A splice variant of IGF-1 produced in response to mechanical stress on muscles, promoting satellite cell activation and muscle repair.

A PEGylated version of MGF with extended half-life for systemic muscle growth and recovery effects.

A neuropeptide that regulates wakefulness, arousal, and appetite. Its deficiency causes narcolepsy.

A CNTF-derived peptide that promotes neurogenesis and has shown promise in Alzheimer's disease research.

An enhanced version of Epithalon with improved stability, studied for telomerase activation, pineal gland regulation, and anti-aging effects.

A synthetic exercise mimetic that activates estrogen-related receptors (ERRs) to replicate the molecular effects of aerobic exercise — increasing endurance, fat oxidation, and mitochondrial function without physical activity.

A synthetic tripeptide that mimics Temple Pit Viper venom, blocking muscular acetylcholine receptors to reduce dynamic wrinkles. Often called 'topical Botox' — reduces muscle contractions by 82% in vitro.

A selective NNMT inhibitor that reduces fat mass by boosting NAD+ and cellular energy expenditure — without affecting appetite. In mice, 11 days of treatment produced 5% weight loss and 35% reduction in white adipose tissue.

A naturally occurring antimicrobial peptide that plays a key role in innate immune defense.

A potent angiotensin IV analog studied for cognitive enhancement. Its Dihexa-derived prodrug fosgonimeton failed its Phase 2/3 Alzheimer's trial (LIFT-AD, 2024), and the foundational 2014 HGF/c-Met mechanism paper was retracted in 2025 — material context that reshapes how the preclinical literature should be read.

A naturally occurring neuropeptide that modulates sleep patterns and has been studied for insomnia and stress.

A cosmetic peptide that reduces the appearance of wrinkles by modulating neuromuscular junction signaling.

A mitochondria-derived peptide that regulates metabolic homeostasis and has been called an 'exercise mimetic.'

A synthetic peptide derived from sortilin that acts as a TREK-1 channel blocker, studied as a rapid-acting antidepressant alternative.

An experimental fat-targeting peptide that selectively destroys blood vessels feeding white adipose tissue. Produced dramatic fat loss in primate studies but was discontinued due to kidney toxicity.

A synthetic signal peptide that mimics thrombospondin-1 to activate TGF-beta signaling, stimulating type I and III collagen production in dermal fibroblasts for anti-wrinkle and skin-firming effects.

A synthetic enkephalin-mimicking pentapeptide that reduces acetylcholine release at the neuromuscular junction, relaxing facial muscles and smoothing expression wrinkles. Reduces wrinkle depth by ~11% alone and up to 25% when combined with Argireline.

A synthetic pentapeptide inspired by Temple Pit Viper venom that competitively blocks nicotinic acetylcholine receptors, reducing muscle contraction and expression wrinkles by up to 49% in 28 days.

An exercise-induced myokine that promotes browning of white adipose tissue, enhances metabolism, and shows neuroprotective effects — though bioavailability and clinical translation remain challenging.

An endogenous TGF-β superfamily peptide closely related to myostatin (~90% identity in mature domain), launched into mainstream attention by Loffredo and Wagers' 2013 Cell paper claiming circulating GDF-11 declines with age and reverses cardiac hypertrophy in aged mice — a rejuvenation story that has been substantially complicated by Egerman, Glass, and others' contradicting work showing antibody specificity issues, GDF-11 increases (not decreases) with age in some populations, and direct GDF-11 administration may worsen rather than improve outcomes.

A short tripeptide studied for neuroprotective and cognitive-enhancing properties, part of the Khavinson peptide bioregulator family.

A zinc-dependent thymic peptide involved in T-cell maturation, studied for immune restoration and anti-inflammatory applications.

A synthetic peptide bioregulator targeting brain cortex function, studied for cognitive enhancement and neuroprotection in aging.

A synthetic tripeptide bioregulator (Lys-Glu-Asp) from the Khavinson system, studied for vascular protection, endothelial function, and age-related cardiovascular decline.

A synthetic tetrapeptide bioregulator (Lys-Glu-Asp-Trp) from the Khavinson system, studied for pancreatic function, glucose metabolism, and age-related type 2 diabetes.

A synthetic tripeptide bioregulator (Ala-Glu-Asp) from the Khavinson system, studied for cartilage protection, joint health, and musculoskeletal aging.

A naturally occurring immunopeptide that controls T cell migration into inflamed tissues. Discovered at the University of Birmingham, PEPITEM shows preclinical promise for inflammatory arthritis, multiple sclerosis, lupus, psoriasis, bone loss, and age-related immune decline.

A chimeric anticancer peptide that selectively kills cancer cells by binding to HDM-2 on their membranes, inducing pore formation and necrosis while leaving normal cells unharmed.

An immunomodulatory tetrapeptide derived from human IgG, used in cosmeceuticals as Palmitoyl Tetrapeptide-7 to suppress skin inflammation (IL-6) and support anti-aging skin repair.

A palmitoylated cosmeceutical tripeptide (Ala-His-Lys) studied for hair growth stimulation via dermal papilla cell proliferation and anti-apoptotic signaling, as well as collagen synthesis and skin rejuvenation.

A synthetic immunomodulatory dipeptide (Glu-Trp) isolated from the thymic peptide complex Thymalin, studied for T-cell differentiation, anti-aging immune restoration, and anti-inflammatory activity as part of the Khavinson bioregulator system.

A synthetic decapeptide (Arg-Asp-Gly-Gln-Ile-Leu-Ser-Thr-Trp-Tyr) marketed as the active in β-WHITE™, positioned as a topical skin-brightening ingredient that suppresses MITF-driven melanogenesis rather than directly inhibiting tyrosinase.

A low-molecular-weight dimeric dipeptide mimetic of nerve growth factor's fourth beta-turn loop, designed to reproduce NGF's neurotrophic effects at TrkA without the pain-sensitizing side effects of full-length NGF.

A low-molecular-weight dimeric dipeptide mimetic of the fourth loop of brain-derived neurotrophic factor (BDNF), designed at the Zakusov Institute in Moscow and studied preclinically as an antidepressant and neuroprotective agent.

A copper peptide — the copper-complexed tripeptide alanine-histidine-lysine (AHK-Cu, Copper Tripeptide-3) — studied for hair follicle stimulation and dermal papilla cell survival. A structural cousin of the better-known copper peptide GHK-Cu with a distinct, hair-focused research profile.

A 23-amino-acid peptide proposed in 2005 by Aaron Hsueh's group at Stanford as a ghrelin-opposing anorectic hormone encoded by the same preproghrelin gene, with a contested physiological role — the original Science paper has been only partially replicated, and obestatin's identity as a true ghrelin antagonist on food intake remains one of the most public failure-to-replicate stories in peptide endocrinology.

A cosmetic tetrapeptide marketed for under-eye puffiness and dark circles, developed by Lipotec (now Lubrizol Life Science) and used in topical cosmetic formulations targeting periorbital edema, glycation reduction, and capillary permeability — with the standard cosmetic-grade evidence base of in-house formulation studies rather than independently published peer-reviewed clinical trials.

A 5-residue active fragment of the 49-residue thymic peptide thymopoietin, characterized in the late 1970s and 1980s as an immunomodulator with effects on T-cell maturation. Used historically as an investigational and limited-clinical agent (Timunox in some markets) for chronic immune dysfunction including atopic dermatitis and rheumatoid arthritis, with the short plasma half-life (Tischio 1979) limiting practical clinical translation.

The natural-extract pineal-tissue polypeptide preparation that preceded synthetic Epitalon (KEDG) in the Khavinson program. Anisimov's 1998 Mech Ageing Dev paper reported lifespan extension of fruit flies, mice, and rats by Epithalamin — one of the most-cited Russian-tradition peptide aging studies. Distinct from synthetic Epitalon: Epithalamin is the older complex polypeptide preparation, Epitalon is the chemically defined tetrapeptide identified as a key active component.

A synthetic dipeptide bioregulator (Glu-Asp) from the Khavinson system, studied for bladder function support, urinary health, and age-related urogenital decline.

A synthetic tetrapeptide bioregulator (Lys-Glu-Asp-Ala) from the Khavinson system, studied for chromatin decondensation, hepatoprotection, and immune cell reactivation in aging.

A synthetic tripeptide bioregulator (Glu-Asp-Gly) from the Khavinson system, studied for respiratory and bronchial mucosal health, anti-inflammatory gene regulation, and stress protection in lung tissue.

A naturally occurring heptapeptide from frog skin and one of the most potent mu-opioid receptor agonists known, approximately 40 times more potent than morphine.

A milk-derived hexapeptide from bovine beta-casein with immunomodulatory, anticancer, and hepatoprotective properties studied primarily in ovarian cancer and liver disease models.

A liver- and brain-derived peptide hormone that regulates energy balance, insulin sensitivity, and endothelial function — investigated as both a cardiometabolic biomarker and a potential therapeutic target, though no clinical drug program exists yet.

A yeast-derived cosmetic hexapeptide that activates the proteasome, autophagy, and antioxidant response pathways in skin fibroblasts — positioned as a proteostasis-based anti-aging ingredient.

An endogenous tetrapeptide cleaved from thymosin β4 with broad antifibrotic activity across the heart, kidney, lung, and liver — historically developed as the chemoprotective drug goralatide and more recently studied as a biomarker of ACE-inhibitor activity.

A 14-amino-acid peptide hormone that activates galanin receptors 2 and 3 — lower in obesity and type 2 diabetes, investigated as a potential metabolic therapeutic and biomarker but still without any approved product or clinical trial program.

A nine-amino-acid cosmetic peptide designed as an α-MSH antagonist at the MC1R receptor on melanocytes, formulated topically as a skin-brightening and anti-hyperpigmentation ingredient.

A palmitoyl-conjugated dipeptide cosmetic ingredient marketed as a retinol-like anti-aging active — positioned for fine-line reduction and skin smoothing via fibroblast and extracellular-matrix signaling rather than retinoic-acid-receptor activation.

A collagen-derived tripeptide (glycine-proline-hydroxyproline) that is the most abundant repeating motif in type I collagen — used as a cosmetic INCI ingredient in topical formulations and present in oral collagen hydrolysate supplements marketed for skin and joint support.

A synthetic immunomodulatory dipeptide (Lys-Glu) isolated from the thymic peptide complex Thymalin, studied by the Khavinson group for T-cell support, gene-expression modulation, and lifespan endpoints in aging rodents.

A synthetic tetrapeptide bioregulator (Ala-Glu-Asp-Leu) from the Khavinson system, studied for bronchial epithelial maintenance, mucin gene regulation, and adjunct use in chronic bronchitis and COPD within the Russian bioregulator framework.

A synthetic short peptide bioregulator (commonly cited as the tripeptide Ala-Glu-Asp) from the Khavinson program, positioned as a myocardial tissue-specific regulator and studied in rodent cardiac and tumor models for age-related cardiac function decline.

A synthetic short peptide bioregulator (commonly cited as the tetrapeptide Lys-Glu-Asp-Pro) from the Khavinson program, positioned as a prostate-tissue-specific regulator and studied in rodent models for benign prostatic hyperplasia, chronic prostatitis, and age-related prostate function decline.

A synthetic tetrapeptide bioregulator (commonly cited as Lys-Glu-Asp-Gly, KEDG) from the Khavinson program, positioned as the testicular tissue-targeted short peptide and discussed for age-related decline in Leydig cell function, male reproductive aging, and androgen deficiency.

A 32-amino-acid endogenous peptide hormone that acts as the second ligand of the APJ (apelin) receptor — essential for embryonic cardiovascular development and emerging as a candidate therapeutic for pulmonary hypertension, pre-eclampsia, heart failure, and chronic kidney disease. Currently a research molecule with no approved clinical product.

The original synthetic growth hormone-releasing peptide developed by Cyril Bowers and Frank Momany in the late 1970s through structural optimization of Met-enkephalin — the historical seed of the GHRP class that gave rise to GHRP-2, GHRP-6, hexarelin, and ipamorelin, and the discovery program that eventually led to the identification of the ghrelin receptor (GHSR1a).

A synthetic short peptide (commonly cited as Glu-Asp-Pro, EDP) from the Khavinson program at the St. Petersburg Institute of Bioregulation and Gerontology, positioned as the thymus / immune-system tissue-targeted bioregulator and the synthetic counterpart to the natural-extract preparation Thymalin — used within the Khavinson framework for age-related immune decline, with the thinnest peer-reviewed footprint in the bioregulator catalog.

A 5-residue peptide derived from splenopoietin (the spleen-derived counterpart to thymopoietin) and characterized in the late 1980s and 1990s as an immunomodulator alongside the closely related thymopentin (TP-5). Singh and Biswas's 1998 Immunology Research review established splenopentin and thymopentin as paired immunomodulatory pentapeptides; the molecule has remained research-tier without clinical translation.

A natural-extract retinal-tissue polypeptide preparation in the Khavinson catalog, used in Russian ophthalmology practice for diabetic retinopathy, retinitis pigmentosa, and other retinal disorders. Khavinson's group has studied Visoluten in retinal aging and dystrophic disease (Trofimova 2001, Khavinson 2014), with the broader Khavinson framework's mechanistic and evidence limitations applying.

The N-terminal propeptide domain of myostatin that remains non-covalently bound to mature myostatin in latent extracellular complexes — characterized by Hill, Lee, and colleagues (JBC 2002, Mol Endocrinol 2003) as one of the principal endogenous inhibitors of myostatin signaling, alongside follistatin and the GASP-1/GASP-2 follistatin-related proteins. Studied as a research-tier myostatin antagonism strategy in muscular dystrophy, sarcopenia, and muscle-wasting models.

A neuropeptide encoded in the same prepronociceptin gene as nociceptin/orphanin FQ that functionally opposes nociceptin's actions — attenuating allodynia and hyperalgesia in animal models through a receptor system distinct from the NOP receptor.

An amphibian skin-derived cationic antimicrobial peptide from the Phyllomedusa sauvagii frog, studied in vitro for antibacterial, antifungal, antiparasitic, and antiviral membrane-disrupting activity. "DS5" is an ambiguous label across the peptide literature; this entry covers dermaseptin S5 specifically.

A chemically modified version of Semax designed for improved stability. No published clinical or preclinical data exists for this specific compound.

A once-monthly dual GIP/GLP-1 receptor agonist from Eli Lilly, in Phase 3 trials for alcohol use disorder and bipolar disorder, with additional studies in obesity, asthma, and smoking cessation.

An enhanced derivative of Semax with N-terminal acetylation and C-terminal adamantane modification, engineered for superior blood-brain barrier penetration, BDNF upregulation, and sustained nootropic effects.

A synthetic tripeptide bioregulator (Glu-Asp-Leu) from the Khavinson system, studied for liver tissue support, hepatoprotection, and gastrointestinal health.

A 33-residue single-chain peptide derivative of human relaxin-2 designed by Mohammed Akhter Hossain's group at the Florey Institute as a functionally selective RXFP1 agonist with improved chemical stability and synthesis tractability over the two-chain native relaxin scaffold — replicates serelaxin's vasodilatory and antifibrotic effects in preclinical models.

A research-channel-only peptide listing with no peer-reviewed PubMed footprint, no characterized mechanism in mainstream literature, and no FDA-approval pathway. Sold as a research chemical through some peptide vendors but with essentially no validated clinical or biological evidence base — positioning is unclear and the molecule should be treated as a marketing-tier listing rather than a pharmacologically validated peptide.