Peptide Database
86 therapeutic peptides with research summaries, clinical findings, and regulatory status.
Pentosan Polysulfate (Elmiron)
A semi-synthetic sulfated polysaccharide derived from beechwood hemicellulose with structural similarities to glycosaminoglycans. Pentosan polysulfate replenishes the defective glycosaminoglycan layer of the bladder urothelium in interstitial cystitis, reducing urothelial permeability to irritants. It also exhibits anti-inflammatory, anticoagulant, and fibrinolytic properties through inhibition of complement activation and mast cell histamine release.
Semaglutide (Ozempic/Wegovy)
A glucagon-like peptide-1 receptor agonist (GLP-1 RA) with 94% amino acid homology to native GLP-1. Semaglutide enhances glucose-dependent insulin secretion, suppresses glucagon, delays gastric emptying, and acts on hypothalamic GLP-1 receptors to reduce appetite. Its fatty acid side chain enables albumin binding, extending its half-life to approximately 7 days.
Tirzepatide (Mounjaro/Zepbound)
A first-in-class dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist. Tirzepatide activates both incretin pathways simultaneously, producing superior glycemic control and weight loss compared to selective GLP-1 RAs. The dual mechanism enhances insulin sensitivity and lipid metabolism beyond what either pathway achieves alone.
Liraglutide (Saxenda/Victoza)
A GLP-1 receptor agonist with 97% homology to native GLP-1, modified with a fatty acid side chain (C-16 palmitoyl) enabling albumin binding and a half-life of approximately 13 hours. Liraglutide enhances glucose-dependent insulin secretion, suppresses glucagon, delays gastric emptying, and promotes satiety through hypothalamic GLP-1R activation. It was the first GLP-1 RA approved for chronic weight management.
Exenatide (Byetta/Bydureon)
A synthetic version of exendin-4, a 39-amino acid peptide originally isolated from the saliva of the Gila monster lizard (Heloderma suspectum). Exenatide shares 53% homology with human GLP-1 and is resistant to DPP-4 degradation. It activates GLP-1 receptors to enhance insulin secretion, suppress glucagon, slow gastric emptying, and promote beta-cell preservation.
Glucagon
A 29-amino acid peptide hormone produced by alpha cells of the pancreatic islets of Langerhans. Glucagon acts primarily on hepatocytes via the glucagon receptor (GCGR), a G-protein-coupled receptor that activates adenylyl cyclase, increasing cAMP and triggering glycogenolysis and gluconeogenesis to raise blood glucose. It also relaxes smooth muscle of the GI tract and has positive inotropic and chronotropic cardiac effects.
Pramlintide (Symlin)
A synthetic analog of amylin (islet amyloid polypeptide), a 37-amino acid peptide hormone co-secreted with insulin from pancreatic beta cells. Pramlintide has three proline substitutions that prevent amyloid fibril formation while retaining amylin receptor activity. It slows gastric emptying, suppresses postprandial glucagon secretion, and promotes satiety via area postrema activation, complementing insulin therapy in diabetes management.
Dulaglutide (Trulicity)
A long-acting GLP-1 receptor agonist consisting of a GLP-1 analog covalently linked to a modified human IgG4 Fc fragment via a peptide linker. This fusion protein design increases molecular size to reduce renal clearance and enables FcRn-mediated recycling, producing a half-life of approximately 5 days suitable for once-weekly dosing. Dulaglutide activates pancreatic GLP-1 receptors to enhance glucose-dependent insulin secretion and suppress glucagon.
Lixisenatide (Adlyxin)
A selective GLP-1 receptor agonist derived from exendin-4 with a modified C-terminal tail containing six lysine residues. Lixisenatide has a half-life of approximately 3 hours and primarily reduces postprandial glucose through potent delay of gastric emptying rather than fasting glucose reduction. It is designed for once-daily use as an add-on to basal insulin therapy in type 2 diabetes.
Setmelanotide (Imcivree)
A cyclic peptide melanocortin-4 receptor (MC4R) agonist designed to restore MC4R signaling in patients with obesity caused by genetic deficiencies in the leptin-melanocortin pathway. Setmelanotide bypasses upstream defects in POMC, PCSK1, or LEPR genes by directly activating MC4R, reducing hunger and increasing energy expenditure. It represents one of the first precision medicines for genetically defined obesity.
Sermorelin
A synthetic 29-amino acid analog of GHRH representing the shortest fully functional fragment of the native 44-amino acid hormone. Sermorelin stimulates the pituitary to produce and release growth hormone through the natural GHRH receptor pathway, preserving the hypothalamic-pituitary feedback axis. It maintains physiological pulsatile GH secretion patterns.
Tesamorelin (Egrifta)
A synthetic GHRH analog consisting of the 44-amino acid sequence of human GHRH with a trans-3-hexenoic acid modification at the N-terminus to improve stability. Tesamorelin specifically targets visceral adipose tissue reduction by stimulating lipolysis through GH-mediated pathways. It is the only FDA-approved treatment for HIV-associated lipodystrophy.
PT-141 (Bremelanotide / Vyleesi)
A synthetic cyclic heptapeptide melanocortin receptor agonist that activates MC3R and MC4R in the central nervous system. Unlike PDE5 inhibitors that act peripherally on vascular smooth muscle, PT-141 works centrally through hypothalamic melanocortin pathways that modulate sexual arousal and desire. It is a metabolite of Melanotan II without significant melanogenic activity.
Oxytocin
A nine-amino acid cyclic neuropeptide produced in the hypothalamus and released from the posterior pituitary. Oxytocin mediates uterine contractions during labor, milk ejection during lactation, and social bonding behaviors. It modulates the HPA stress axis, reduces cortisol, and has anxiolytic properties. Intranasal administration reaches the CNS through olfactory and trigeminal nerve pathways.
Macimorelin (Macrilen)
An orally bioavailable growth hormone secretagogue approved as a diagnostic agent for adult growth hormone deficiency (AGHD). Macimorelin stimulates GH release via GHS-R1a agonism, and the GH response to a standardized oral dose is used to confirm or exclude AGHD. It offers a simpler, better-tolerated alternative to the insulin tolerance test and GHRH-arginine test for GH deficiency diagnosis.
Cosyntropin (Cortrosyn)
A synthetic peptide consisting of the first 24 amino acids of the 39-amino acid adrenocorticotropic hormone (ACTH). Cosyntropin retains full biological activity of native ACTH for stimulating adrenal cortisol production and is used as a diagnostic agent in the ACTH stimulation test to evaluate adrenal gland function. It binds to the MC2R receptor on adrenocortical cells, activating steroidogenesis.
Gonadorelin (GnRH)
A synthetic decapeptide identical to endogenous gonadotropin-releasing hormone. Gonadorelin stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary when administered in a pulsatile fashion. Continuous or high-dose administration paradoxically downregulates GnRH receptors, suppressing gonadotropin secretion, a principle exploited by GnRH agonist therapeutics.
Leuprolide (Lupron)
A synthetic nonapeptide GnRH agonist approximately 15-fold more potent than native GnRH. After an initial stimulatory phase (flare effect) lasting 1-2 weeks, chronic leuprolide administration downregulates pituitary GnRH receptors, resulting in profound suppression of LH, FSH, and downstream sex steroids. This chemical castration effect is exploited in treating hormone-sensitive cancers, endometriosis, and precocious puberty.
Goserelin (Zoladex)
A synthetic decapeptide GnRH agonist administered as a biodegradable subcutaneous implant that provides sustained drug release over 1 or 3 months. Like other GnRH agonists, goserelin initially stimulates and then suppresses the HPG axis, reducing sex hormone production to castrate or postmenopausal levels. The implant formulation eliminates the need for repeated injections and ensures compliance.
Cetrorelix (Cetrotide)
A synthetic decapeptide GnRH antagonist that competitively blocks pituitary GnRH receptors, producing immediate and dose-dependent suppression of LH and FSH without the initial flare effect seen with GnRH agonists. Cetrorelix prevents premature LH surges during controlled ovarian stimulation in IVF, allowing precise timing of oocyte maturation and retrieval.
Ganirelix
A synthetic decapeptide GnRH antagonist that competitively and reversibly blocks GnRH receptors on pituitary gonadotroph cells. Ganirelix rapidly suppresses LH secretion within hours of administration, preventing premature ovulation during assisted reproductive technology (ART) cycles. Its mechanism provides immediate suppression without the flare phase associated with GnRH agonists.
Semax
A synthetic heptapeptide analog of the ACTH(4-7) fragment (Met-Glu-His-Phe-Pro-Gly-Pro) with nootropic and neuroprotective properties. Semax modulates BDNF and NGF expression, enhances monoaminergic neurotransmission, and provides neuroprotection through anti-oxidant and anti-inflammatory mechanisms. It crosses the blood-brain barrier via intranasal administration.
Enfuvirtide (Fuzeon)
A 36-amino acid synthetic peptide that inhibits HIV-1 entry into CD4+ T-cells by blocking the gp41-mediated membrane fusion step. Enfuvirtide binds to the first heptad repeat (HR1) region of gp41, preventing the conformational change required for viral-cell membrane fusion. It is the first and only FDA-approved fusion inhibitor and is active against HIV-1 strains resistant to other antiretroviral drug classes.
Teriparatide (Forteo)
A recombinant form of the first 34 amino acids of human parathyroid hormone (PTH 1-34). When administered intermittently via daily subcutaneous injection, teriparatide stimulates osteoblastic bone formation more than osteoclastic resorption, producing a net anabolic effect on bone. It activates the PTH1 receptor on osteoblasts, increasing Wnt signaling, osteoblast differentiation, and survival while reducing sclerostin expression.
Abaloparatide (Tymlos)
A synthetic 34-amino acid peptide analog of parathyroid hormone-related protein (PTHrP 1-34) that selectively activates the RG conformation of the PTH1 receptor. This receptor selectivity produces a more transient signaling response compared to teriparatide, favoring anabolic bone formation with less stimulation of bone resorption and calcium mobilization. Abaloparatide increases bone mineral density at both cortical and trabecular sites.
Calcitonin
A 32-amino acid peptide hormone naturally produced by parafollicular C-cells of the thyroid gland. Calcitonin inhibits osteoclast-mediated bone resorption by binding to calcitonin receptors on osteoclasts, reducing their activity and number. Salmon calcitonin is approximately 40-50 times more potent than human calcitonin and has a longer half-life, making it the preferred therapeutic form.
Vosoritide (Voxzogo)
A C-type natriuretic peptide (CNP) analog that acts as an agonist at the natriuretic peptide receptor B (NPR-B) on growth plate chondrocytes. Vosoritide counteracts the constitutively activated FGFR3 signaling that suppresses endochondral ossification in achondroplasia. By stimulating the NPR-B/cGMP/MAPK pathway, it antagonizes the growth-inhibitory FGFR3 signal and restores more normal linear bone growth.
Vasopressin (ADH)
A nine-amino acid cyclic peptide hormone (arginine vasopressin) produced in the hypothalamus and released from the posterior pituitary. Vasopressin acts on V1a receptors (vascular smooth muscle vasoconstriction), V1b receptors (ACTH release from pituitary), and V2 receptors (aquaporin-2 insertion in renal collecting ducts for water reabsorption). It is essential for body water homeostasis and hemodynamic stability.
Desmopressin (DDAVP)
A synthetic analog of vasopressin with enhanced V2 receptor selectivity and minimal V1a vasopressor activity. Desmopressin has a deaminated cysteine at position 1 and D-arginine at position 8, increasing its antidiuretic potency 10-fold while largely eliminating the hypertensive effects of native vasopressin. Its prolonged half-life of 2-4 hours (vs. 10-20 minutes for vasopressin) allows convenient dosing for chronic conditions.
Terlipressin
A synthetic vasopressin analog and prodrug that is cleaved by endopeptidases to release lysine-vasopressin. Terlipressin has greater V1a receptor selectivity than vasopressin, producing splanchnic vasoconstriction that reduces portal pressure and redistributes blood flow to the kidneys. This mechanism addresses the pathophysiology of hepatorenal syndrome (HRS) by counteracting the splanchnic vasodilation that drives renal hypoperfusion.
Eptifibatide (Integrilin)
A synthetic cyclic heptapeptide modeled after the KGD (Lys-Gly-Asp) disintegrin sequence found in the venom of the southeastern pygmy rattlesnake (Sistrurus miliarius barbouri). Eptifibatide is a potent, reversible glycoprotein IIb/IIIa receptor antagonist that blocks the final common pathway of platelet aggregation by preventing fibrinogen and von Willebrand factor binding to activated platelets.
Nesiritide (Natrecor)
A recombinant form of human B-type natriuretic peptide (BNP), a 32-amino acid peptide naturally produced by ventricular cardiomyocytes in response to volume overload and wall stress. Nesiritide binds natriuretic peptide receptor A (NPR-A), activating guanylyl cyclase and increasing intracellular cGMP to produce venous, arterial, and coronary vasodilation, natriuresis, and suppression of the renin-angiotensin-aldosterone and sympathetic nervous systems.
Angiotensin II (Giapreza)
A synthetic form of the endogenous octapeptide angiotensin II, the primary effector of the renin-angiotensin system. Angiotensin II acts on AT1 receptors on vascular smooth muscle to produce potent vasoconstriction, and on the adrenal cortex to stimulate aldosterone release. Exogenous administration raises blood pressure in vasodilatory shock refractory to conventional vasopressors by restoring vascular tone through a mechanism complementary to catecholamine vasopressors.
Bivalirudin (Angiomax)
A synthetic 20-amino acid peptide that acts as a direct thrombin inhibitor by binding both the catalytic active site and anion-binding exosite 1 of thrombin. Bivalirudin inhibits both free and clot-bound thrombin, providing more predictable anticoagulation than heparin without requiring antithrombin III as a cofactor. It is enzymatically cleaved by thrombin itself, producing a self-limiting anticoagulant effect with a 25-minute half-life.
Romiplostim (Nplate)
A thrombopoietin (TPO) receptor agonist consisting of a peptide sequence that binds the TPO receptor (c-Mpl) fused to an IgG1 Fc domain (peptibody). Romiplostim activates JAK2/STAT5 signaling in megakaryocyte progenitors, promoting megakaryocyte proliferation, differentiation, and platelet production. It has no sequence homology to endogenous TPO, minimizing the risk of cross-reactive antibody formation.
Pegcetacoplan (Empaveli)
A pegylated cyclic peptide that inhibits complement component C3, the central node of all three complement activation pathways (classical, lectin, and alternative). By binding C3 and preventing its cleavage into C3a and C3b, pegcetacoplan blocks both intravascular hemolysis (mediated by membrane attack complex) and extravascular hemolysis (mediated by C3b opsonization and phagocytosis). This dual mechanism addresses the limitation of C5 inhibitors that only prevent intravascular hemolysis.
Carfilzomib (Kyprolis)
A tetrapeptide epoxyketone proteasome inhibitor that irreversibly binds the chymotrypsin-like (beta5) subunit of the 20S proteasome. By blocking proteasomal degradation of ubiquitinated proteins, carfilzomib causes accumulation of misfolded proteins, endoplasmic reticulum stress, and activation of the unfolded protein response, leading to apoptosis preferentially in malignant plasma cells. Its irreversible binding confers greater proteasome inhibition than bortezomib.
Bortezomib (Velcade)
A modified dipeptidyl boronic acid that reversibly inhibits the chymotrypsin-like activity of the 26S proteasome. Bortezomib disrupts the ubiquitin-proteasome pathway, stabilizing pro-apoptotic factors and inhibiting NF-kB activation, which is constitutively active in many hematologic malignancies. It was the first proteasome inhibitor approved for cancer treatment and fundamentally changed the treatment landscape of multiple myeloma.
Lutetium-177 dotatate (Lutathera)
A radiolabeled somatostatin analog consisting of the peptide DOTA-Tyr3-octreotate chelated to the beta-emitting radioisotope lutetium-177. Lutathera binds with high affinity to somatostatin receptor subtype 2 (SSTR2), which is overexpressed on neuroendocrine tumor cells, delivering targeted radiation therapy directly to tumor cells while sparing surrounding normal tissue. This peptide receptor radionuclide therapy (PRRT) approach combines receptor-targeted delivery with cytotoxic radiation.
Leuprolide (Lupron) - Oncology
A GnRH agonist used in oncology for androgen deprivation therapy (ADT) in prostate cancer and hormone suppression in premenopausal breast cancer. Chronic administration produces sustained downregulation of pituitary GnRH receptors, achieving medical castration with testosterone levels below 50 ng/dL. The initial testosterone flare can be mitigated by co-administration of an antiandrogen. Depot formulations provide sustained release for up to 6 months.
Octreotide (Sandostatin)
A synthetic octapeptide analog of somatostatin with a substantially longer half-life (90 minutes IV, 6 hours subcutaneous vs. 2 minutes for native somatostatin). Octreotide binds somatostatin receptors (primarily SSTR2 and SSTR5) to inhibit the secretion of GH, glucagon, insulin, gastrin, secretin, VIP, and other GI hormones. It reduces splanchnic blood flow, GI motility, and exocrine pancreatic secretion.
Lanreotide (Somatuline Depot)
A synthetic octapeptide analog of somatostatin with high affinity for SSTR2 and moderate affinity for SSTR5 receptors. Lanreotide is formulated as a supersaturated solution that forms a drug depot at the injection site, providing sustained release over 4 weeks. It inhibits GH secretion, GI hormone release, and has direct antiproliferative effects on neuroendocrine tumor cells through cell cycle arrest and apoptosis induction.
Pasireotide (Signifor)
A multireceptor-targeted somatostatin analog with high binding affinity for SSTR1, SSTR2, SSTR3, and SSTR5, particularly notable for its 40-fold greater affinity for SSTR5 compared to octreotide. This receptor profile makes pasireotide uniquely effective in Cushing's disease, where corticotroph adenomas predominantly express SSTR5. Pasireotide suppresses ACTH secretion from pituitary corticotroph tumors, reducing cortisol production.
Plecanatide (Trulance)
A synthetic 16-amino acid peptide structurally related to uroguanylin, an endogenous intestinal peptide that regulates fluid and electrolyte homeostasis in the GI tract. Plecanatide activates guanylate cyclase-C (GC-C) receptors on intestinal epithelial cells in a pH-dependent manner, preferentially in the proximal small intestine where pH is slightly acidic. GC-C activation increases intracellular and extracellular cGMP, stimulating chloride and bicarbonate secretion while reducing visceral pain signaling.
Linaclotide (Linzess)
A synthetic 14-amino acid peptide structurally related to the heat-stable enterotoxin of Escherichia coli and the endogenous peptide guanylin. Linaclotide activates guanylate cyclase-C (GC-C) on the luminal surface of intestinal epithelium, increasing intracellular cGMP to stimulate CFTR-mediated chloride and bicarbonate secretion, accelerating intestinal transit. Extracellular cGMP also reduces firing of visceral afferent pain fibers, providing analgesic effects in the gut.
Secretin
A 27-amino acid peptide hormone produced by S-cells of the duodenal and jejunal mucosa in response to acidic chyme entering the small intestine. Secretin stimulates pancreatic ductal cells to secrete bicarbonate-rich fluid, neutralizing duodenal acid, and promotes bile flow from hepatocytes. It was the first hormone ever identified (Bayliss and Starling, 1902) and serves as a key diagnostic tool in gastroenterology and endocrinology.
Ziconotide (Prialt)
A synthetic 25-amino acid peptide identical to omega-conotoxin MVIIA, a neurotoxin found in the venom of the marine cone snail Conus magus. Ziconotide selectively and reversibly blocks N-type voltage-gated calcium channels (Cav2.2) in the dorsal horn of the spinal cord, inhibiting neurotransmitter release from primary afferent nociceptive neurons. It provides analgesia without opioid receptor activation, tolerance development, or respiratory depression.
Difelikefalin (Korsuva)
A selective kappa-opioid receptor (KOR) agonist peptide that does not cross the blood-brain barrier, providing peripheral analgesia and anti-pruritic effects without central opioid side effects such as euphoria, dysphoria, sedation, or addiction. Difelikefalin activates kappa receptors on peripheral sensory neurons and immune cells to reduce itch signaling and inflammation. Its restricted CNS penetration is a deliberate design feature to avoid abuse potential.
Afamelanotide (Scenesse)
A synthetic 13-amino acid analog of alpha-melanocyte-stimulating hormone (alpha-MSH) with a substitution of norleucine at position 4 that confers enhanced potency and enzymatic stability. Afamelanotide activates melanocortin-1 receptors (MC1R) on melanocytes, stimulating eumelanin production independent of UV exposure. The resulting increase in skin eumelanin provides photoprotection by absorbing UV radiation and scavenging reactive oxygen species.
Pentagastrin
A synthetic pentapeptide containing the C-terminal tetrapeptide sequence of gastrin (Trp-Met-Asp-Phe-NH2) linked to beta-alanine. Pentagastrin stimulates gastric acid secretion by binding to cholecystokinin-2 (CCK2) receptors on parietal cells, and stimulates calcitonin release from thyroid C-cells. It has been used as a diagnostic agent for both gastric acid secretory capacity testing and provocative testing for medullary thyroid carcinoma (MTC).
Icatibant (Firazyr)
A synthetic decapeptide bradykinin B2 receptor antagonist containing five non-natural amino acids for enhanced stability and receptor selectivity. Icatibant competitively blocks bradykinin, the primary mediator of swelling in hereditary angioedema (HAE) caused by C1 esterase inhibitor deficiency. By preventing bradykinin-induced vasodilation and increased vascular permeability, it rapidly reverses mucosal and subcutaneous edema.