Browse more peptide research, methods and limitations.
Single SC CJC-1295 injection in healthy adults produced dose-dependent sustained GH pulsatility and IGF-1 elevation lasting 6-14 days depending on dose, with 2-3 fold IGF-1 increase maintained for up to 2 weeks — the most sustained GH-axis restoration from a single peptide dose.
Teichman, Sam L; Neale, Ann; Lawrence, Betty; Gagnon, Catherine; Castaigne, Jean-Paul; Frohman, Lawrence A · RCT
Ghrelin's clinical applications span GH deficiency diagnosis/treatment, cachexia therapy (cancer, COPD, heart failure), gastroparesis treatment, cardiovascular protection, and appetite disorders — the most comprehensive clinical potential for any single peptide hormone.
Tritos, Nicholas A; Kokkotou, Efi G · Review
The enzyme prohormone convertase 1/3 (PC1/3) is the essential scissor that cuts the GIP precursor protein into active GIP — one of the two incretin hormones that stimulate insulin release after eating. In mice lacking PC1/3, GIP production was severely impaired. A different enzyme, PC2, can technically cut the GIP precursor but produces abnormal fragments not found in the intestine and is not present in GIP-producing cells. The researchers confirmed this through multiple approaches: immunohistochemistry showed GIP and PC1/3 co-localize in the same intestinal cells (but PC2 does not), knockout mice lacking PC1/3 had dramatically reduced GIP, and cell line experiments confirmed PC1/3 alone is sufficient to produce active GIP.
Ugleholdt, Randi; Poulsen, Marie-Louise H; Holst, Peter J; Irminger, Jean-Claude; Orskov, Cathrine; Pedersen, Jens; Rosenkilde, Mette M; Zhu, Xiaorong; Steiner, Donald F; Holst, Jens J · Basic Science (Animal + Cell Line)
Gastric accommodation, sensitivity, emptying, and gut hormones (ghrelin, CCK, PYY) showed progressive changes from normal through overweight to obese, with disrupted fasting/postprandial hormone profiles providing the hormonal basis for weight-dependent appetite dysfunction.
Vazquez Roque, Maria I; Camilleri, Michael; Stephens, Debra A; Jensen, Michael D; Burton, Duane D; Baxter, Kari L; Zinsmeister, Alan R · Cross Sectional
Wheat fiber modified postprandial PYY and ghrelin responses without immediate appetite changes, suggesting fiber-induced gut hormone modulation requires chronic exposure rather than acute meal effects for meaningful appetite impact.
Weickert, Martin O; Spranger, Joachim; Holst, Jens J; Otto, Bärbel; Koebnick, Corinna; Möhlig, Matthias; Pfeiffer, Andreas F H · RCT
Arginine vasopressin stimulated enkephalin and endorphin synthesis and secretion in the periaqueductal gray, demonstrating vasopressin-opioid peptide cross-talk in the brain's primary descending pain modulation center.
Yang, Jun; Yang, Yu; Xu, Hong-Tao; Chen, Jian-Min; Liu, Wen-Yan; Lin, Bao-Chen · In Vitro
Only arginine vasopressin (not oxytocin or endogenous opioid peptides) in the paraventricular nucleus mediated electroacupuncture-induced analgesia — demonstrating pathway specificity where different brain nuclei use different peptide systems for the same analgesic effect.
Yang, Jun; Liu, Wen-yan; Song, Cao-you; Lin, Bao-cheng · Animal Study
MSG-induced hypothalamic analgesia was mediated through central AVP signaling exclusively, with oxytocin and opioid peptide antagonists having no effect — confirming vasopressin's dominance in hypothalamic pain modulation pathways.
Yang, Jun; Liu, Wen-Yan; Song, Cao-You; Lin, Bao-Cheng · Animal Study
Ovarian steroids (estrogen, progesterone) regulated gastric motility patterns and visceral sensitivity in rats, providing the hormonal mechanism for menstrual cycle-related GI symptom variations experienced by many women.
Yang, Xia; Liu, Ran; Dong, Yan · Animal Study
Recombinant human lysozyme produced in transgenic mouse milk maintained bactericidal activity equivalent to native human lysozyme, validating mammary gland expression as a scalable production platform for bioactive antimicrobial milk proteins.
Yu, Z; Meng, Q; Yu, H; Fan, B; Yu, S; Fei, J; Wang, L; Dai, Y; Li, N · Animal Study
Transcutaneous magnetic stimulation modulated cardiovascular excitatory responses through spinal cord mechanisms involving opioid peptide and nociceptin pathways — establishing a non-invasive approach to modulating cardiovascular autonomic reflexes.
Zhou Yi Syuu, Wei; Hsiao, Ian; Lin, Vernon W H; Longhurst, John C · Animal Study
N-acylation of a human lactoferricin-derived peptide improved membrane selectivity: maintaining or enhancing antibacterial activity while reducing toxicity to human cells — demonstrating lipid modification as a strategy for improving antimicrobial peptide therapeutic windows.
Zweytick, Dagmar; Pabst, Georg; Abuja, Peter M; Jilek, Alexander; Blondelle, Sylvie E; Andrä, Jörg; Jerala, Roman; Monreal, Daniel; Martinez de Tejada, Guillermo; Lohner, Karl · In Vitro
Serial NT-proBNP and BNP measurements over 6 months improved identification of elderly patients with progressive heart failure compared to single baseline measurements, with peptide trajectory providing superior diagnostic and prognostic information.
Alehagen, Urban; Svensson, Erland; Dahlström, Ulf · Cohort
PI3K-gamma was identified as an essential mediator of GLP-2's intestinal mucosal growth effects, with PI3K-gamma knockout mice showing impaired GLP-2-stimulated mucosal proliferation — mapping the signal transduction for gut peptide-driven intestinal repair.
Anini, Younes; Izzo, Angelo; Oudit, Gavin Y; Backx, Peter H; Brubaker, Patricia L · Animal Study
GLP-1 and GIP are both released within minutes of eating and help the body process nutrients by stimulating insulin release from pancreatic beta cells. Both peptides promote beta-cell growth and protect these cells from dying. However, the two peptides differ in important ways. GIP promotes fat storage and strengthens bones by stimulating bone-building cells. GLP-1, on the other hand, slows stomach emptying, suppresses glucagon (a sugar-raising hormone), promotes feelings of fullness, and is associated with weight loss. Both peptides are rapidly broken down by the enzyme DPP-4, which led to two classes of diabetes drugs: degradation-resistant GLP-1 receptor agonists and DPP-4 inhibitors. These therapies lower HbA1c without causing weight gain in people with type 2 diabetes.
Baggio, Laurie L; Drucker, Daniel J · Review
Thymosin alpha-1 activated the TLR9/MyD88/IRF7 pathway in dendritic cells, inducing type I interferon production for anti-murine cytomegalovirus defense — identifying the specific innate immune sensing pathway mediating thymosin alpha-1's antiviral activity.
Bozza, Silvia; Gaziano, Roberta; Bonifazi, Pierluigi; Zelante, Teresa; Pitzurra, Lucia; Montagnoli, Claudia; Moretti, Silvia; Castronari, Roberto; Sinibaldi, Paola; Rasi, Guido; Garaci, Enrico; Bistoni, Francesco; Romani, Luigina · Animal Study
Iron saturation of bovine lactoferrin significantly affected pepsin-generated lactoferricin yield and cationic peptide composition, with lower iron saturation producing more antimicrobial peptide — practical optimization for food-grade production.
Chan, Judy C K; Li-Chan, Eunice C Y · In Vitro
CCK operates as both the primary gut satiety signal (reducing meal size through vagal afferent and brain CCK-A receptors) and a digestive coordinator (gallbladder contraction, pancreatic secretion) — the most comprehensively characterized gut hormone.
Chandra, Rashmi; Liddle, Rodger A · Review
Nociceptin/OFQ blocked spinal antinociception from mu (DAMGO), kappa (U50,488H), and delta (DPDPE) opioid agonists in the cold water tail-flick test, confirming nociceptin as a universal anti-opioid peptide opposing all three opioid receptor systems.
Chen, Xiaohong; Geller, Ellen B; Adler, Martin W · Animal Study
Different prodynorphin-derived peptides (dynorphin A, dynorphin B, alpha-neoendorphin) showed differential kappa receptor regulation: distinct patterns of internalization, signaling efficacy, and receptor recycling — demonstrating biased agonism from endogenous ligands.
Chen, Yong; Chen, Chongguang; Liu-Chen, Lee-Yuan · In Vitro
Mitochondria-targeted peptides (SS-31 and analogs) reduced myocardial infarct size by up to 60% in rat ischemia-reperfusion, with efficacy when given before ischemia or at reperfusion — demonstrating potent cardioprotection through preservation of mitochondrial function.
Cho, Janghyun; Won, Kyungheon; Wu, DunLi; Soong, Yi; Liu, Shaoyi; Szeto, Hazel H; Hong, Mun K · Animal Study
Updated cyclotide review covering chemical synthesis, structure determination, grafting methodology, and expanding biological activities (antimicrobial, anticancer, insecticidal, anti-HIV, uterotonic) — advancing from natural products to engineered drug scaffolds.
Craik, David J; Cemazar, Masa; Daly, Norelle L · Review
Both ghrelin and des-acyl ghrelin stimulated adrenocortical tumor cell proliferation via anti-apoptotic pathway activation (reduced caspase-3, increased Bcl-2), demonstrating pro-tumorigenic ghrelin system activity in adrenal cancer regardless of GHS-R1a-dependent signaling.
Delhanty, P J D; van Koetsveld, P M; Gauna, C; van de Zande, B; Vitale, G; Hofland, L J; van der Lely, A J · In Vitro
Novel triazole derivatives showed nanomolar GHS-R1a binding and functional agonist activity in vitro and GH release in vivo, expanding the structural diversity of non-peptide ghrelin receptor ligands for drug development.
Demange, Luc; Boeglin, Damien; Moulin, Aline; Mousseaux, Delphine; Ryan, Joanne; Bergé, Gilbert; Gagne, Didier; Heitz, Annie; Perrissoud, Daniel; Locatelli, Vittorio; Torsello, Antonio; Galleyrand, Jean-Claude; Fehrentz, Jean-Alain; Martinez, Jean · In Vitro
BPC-157 healed prolonged esophagitis caused by primary pyloric sphincter dysfunction in rats, improving mucosal integrity and sphincter function — demonstrating efficacy in a reflux model where the underlying cause is sphincter failure.
Dobric, Ivan; Drvis, Petar; Petrovic, Igor; Shejbal, Drazen; Brcic, Luka; Blagaic, Alenka Boban; Batelja, Lovorka; Sever, Marko; Kokic, Neven; Tonkic, Ante; Zoricic, Ivan; Mise, Sandro; Staresinic, Mario; Radic, Bozo; Jakir, Ana; Babel, Jaksa; Ilic, Spomenko; Vuksic, Tihomir; Jelic, Ivan; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag · Animal Study
Intranasal oxytocin significantly improved performance on the Reading the Mind in the Eyes test in healthy men, demonstrating enhanced social cognition and emotional theory of mind — a distinct cognitive effect beyond anxiety reduction.
Domes, Gregor; Heinrichs, Markus; Michel, Andre; Berger, Christoph; Herpertz, Sabine C · RCT
C-peptide replacement therapy for 6 months improved sensory nerve conduction velocity (SCV) in type 1 diabetic patients with neuropathy. Both dose groups (1.5 mg/day and 4.5 mg/day) showed similar improvement. In the less severely affected patients (SCV < 2.5 SD below normal at baseline, n=70), SCV improved by 1.0 m/s compared to placebo (p<0.014). The proportion of patients showing SCV improvement >1.0 m/s was significantly greater in C-peptide groups versus placebo (p<0.03). Clinical neurological impairment scores and vibration perception also improved (p<0.011 and p<0.002 respectively). These improvements occurred independently of blood sugar control, which changed similarly across all groups.
Ekberg, Karin; Brismar, Tom; Johansson, Bo-Lennart; Lindström, Per; Juntti-Berggren, Lisa; Norrby, Anders; Berne, Christian; Arnqvist, Hans J; Bolinder, Jan; Wahren, John ·
Thymosin alpha-1 as an influenza vaccine adjuvant improved seroconversion and antibody titers in elderly adults with normally impaired vaccine responses, addressing the immunosenescence that makes influenza vaccination less effective in the aged.
Ershler, William B; Gravenstein, Stefan; Geloo, Zeba S · Review
Immunohistochemical mapping revealed distinct laminar distributions of met-enkephalin, dynorphin, and beta-endorphin in the rostral agranular insular cortex — the brain's emotional pain processing region — providing the opioid peptide architecture for pain affect modulation.
Evans, Joshua M; Bey, Vincent; Burkey, Adam R; Commons, Kathryn G · Animal Study
GH secretagogues reversed age-related GH/IGF-I axis decline in aged rats by restoring hypothalamic GHRH sensitivity and pituitary responsiveness, with combined GHRP + GHRH achieving the most complete axis restoration for anti-aging neuroendocrine therapy.
Frutos, Miriam García-San; Cacicedo, Lucinda; Fernández, Carolina; Vicent, David; Velasco, Beatriz; Zapatero, Helena; Sánchez-Franco, Franco · Animal Study
Des-acyl ghrelin, previously considered inactive at GHS-R1a, demonstrated full agonist activity at the type 1a receptor — challenging the fundamental assumption that only acylated ghrelin has GHS-R activity and redefining des-acyl ghrelin's biological role.
Gauna, Carlotta; van de Zande, Bedette; van Kerkwijk, Anke; Themmen, Axel P N; van der Lely, A J; Delhanty, Patric J D · In Vitro
Mu-opioid receptor function was essential for delta-opioid receptor-mediated anti-hyperalgesia in inflammatory pain, with mu blockade eliminating delta agonist efficacy — demonstrating mu-delta functional dependence and implications for selective opioid drug design.
Gendron, L; Pintar, J E; Chavkin, C · Animal Study
Bicyclic nisin analogs synthesized via ring-closing metathesis retained antimicrobial activity against gram-positive bacteria, validating chemical synthesis approaches for producing and optimizing this clinically important natural cyclic peptide antibiotic.
Ghalit, Nourdin; Reichwein, John F; Hilbers, Hans W; Breukink, Eefjan; Rijkers, Dirk T S; Liskamp, Rob M J · In Vitro
RAMPs regulate adrenomedullin signaling by modifying calcitonin receptor-like receptor (CLR) specificity: RAMP2/RAMP3 create AM receptors, RAMP1 creates CGRP receptor — explaining how one receptor serves multiple peptide ligands through RAMP partnerships.
Gibbons, Carrie; Dackor, Ryan; Dunworth, William; Fritz-Six, Kimberly; Caron, Kathleen M · Review
VIP generates regulatory T-cells, tolerizes dendritic cells, and suppresses Th1/Th17 inflammatory pathways, providing a comprehensive anti-autoimmune mechanism applicable to rheumatoid arthritis, MS, type 1 diabetes, and transplant rejection.
Gonzalez-Rey, Elena; Anderson, Per; Delgado, Mario · Review
GLP-1 receptor agonists and DPP-4 inhibitors exploit the incretin system for diabetes treatment, providing glucose-dependent insulin stimulation, weight loss (GLP-1 agonists), and low hypoglycemia risk — the most significant new diabetes drug class.
Green, Dina E · Review
MCoTI-II was internalized into human cells through macropinocytosis (not receptor-mediated endocytosis), accumulating in cytoplasm — demonstrating that macrocyclic peptide scaffolds can access intracellular targets, dramatically expanding their drug design utility.
Greenwood, Kathryn P; Daly, Norelle L; Brown, Darren L; Stow, Jennifer L; Craik, David J · In Vitro
PYY integrates multiple gut functions: suppresses appetite (Y2R-mediated), slows gastric emptying, reduces intestinal motility, decreases pancreatic secretion, and promotes fluid absorption — PYY deficiency in obesity contributes to the disordered satiety driving overeating.
Grudell, April B M; Camilleri, Michael · Review
Ethanol-induced changes in brain opioid peptides (dynorphin, enkephalin) in adult Wistar rats were modulated by early postnatal environment (maternal separation), demonstrating gene × early environment interaction programming adult opioid system alcohol sensitivity.
Gustafsson, L; Zhou, Q; Nylander, I · Animal Study
Beta-thymosins (thymosin beta-4 predominantly) regulate actin polymerization and exhibit wound healing, anti-inflammatory, angiogenic, and cardioprotective activities — a structurally and functionally distinct peptide family from thymosin alpha-1 with unique therapeutic potential.
Hannappel, E · Review
Medicinal chemistry review of short lactoferricin-derived antibacterial peptides covering: minimal pharmacophore identification, selectivity optimization (bacteria vs human cells), proteolytic stability enhancement, and design rules for drug-like antimicrobial peptides.
Haug, B E; Strøm, M B; Svendsen, J S M · Review
Carbohydrate restriction in metabolic syndrome patients modified gut peptide profiles (reduced ghrelin, altered PYY) and adipokine levels (decreased leptin, increased adiponectin), with hormonal changes correlating with weight loss and improved metabolic markers.
Hayes, Matthew R; Miller, Carla K; Ulbrecht, Jan S; Mauger, Joanna L; Parker-Klees, Lynn; Gutschall, Melissa Davis; Mitchell, Diane C; Smiciklas-Wright, Helen; Covasa, Mihai · Clinical Trial
Melanocyte-stimulating hormone peptides (melanocortins) play previously unrecognized roles in blood pressure regulation and sodium metabolism. Both alpha-MSH and gamma-MSH acutely raise blood pressure and heart rate by stimulating the sympathetic nervous system, but through different receptor mechanisms: alpha-MSH acts via the MC4R receptor, while gamma-MSH likely activates a central sodium channel rather than its MC3R receptor. Paradoxically, gamma-MSH deficiency causes severe salt-sensitive hypertension — meaning too little of this peptide makes blood pressure dangerously responsive to salt intake. Delivering a small dose of gamma-MSH directly into the brain of deficient mice normalizes blood pressure. This salt-sensitive hypertension is also linked to the development of insulin resistance, though the connecting mechanism remains unknown and may involve sympathetic nervous system activation.
Humphreys, Michael H · Review
Lunasin from various Korean soybean varieties inhibited core histone H3 and H4 acetylation in a dose-dependent manner, with the degree of inhibition correlating to the amount of lunasin present. Both natural soy-derived lunasin and synthetic lunasin showed the same activity. Critically for practical relevance, lunasin in enriched soy survived in vitro pepsin digestion and was found intact in blood and liver tissue of rats fed lunasin-enriched soy (LES). The extracted lunasin retained its histone acetylation inhibitory activity, demonstrating oral bioavailability — a rare achievement for a dietary peptide of this size.
Jeong, Hyung Jin; Jeong, Jin Boo; Kim, Dae Seop; de Lumen, Ben O ·
Lunasin isolated from wheat seeds at different developmental stages inhibited core histone H3 and H4 acetylation in a dose-dependent manner. This is significant because histone acetylation is an epigenetic switch that can activate cancer-promoting genes. Key findings included: - Wheat was confirmed as a new dietary source of lunasin (previously found only in soy and barley) - The peptide's identity was confirmed by Western blot and LC-ESI-MS mass spectrometry - Lunasin extracted from livers of rats fed lunasin-enriched wheat also inhibited histone acetylation, confirming the peptide survives digestion intact and bioactive - The amount of lunasin correlated strongly with the degree of histone acetylation inhibition
Jeong, Hyung Jin; Jeong, Jin Boo; Kim, Dae Seop; Park, Jae Ho; Lee, Jung Bok; Kweon, Dae-Hyuk; Chung, Gyu Young; Seo, Eul Won; de Lumen, Ben O ·
Intravenous infusion of pancreatic polypeptide (PP) at 5 pmol/kg per min — half the dose used in prior studies — reduced energy intake by 11% compared to saline in 14 lean volunteers (2440 vs. 2730 kJ; P<0.05). Preprandial hunger scores were also lower in the PP group. Notably, these appetite-suppressing effects were achieved at plasma PP levels within the pathophysiological range seen in patients with pancreatic tumors, rather than at the supraphysiological levels used previously.
Jesudason, David R; Monteiro, Mariana P; McGowan, Barbara M C; Neary, Nicola M; Park, Adrian J; Philippou, Elena; Small, Caroline J; Frost, Gary S; Ghatei, Mohammad A; Bloom, Stephen R · Rct
Thymosin alpha-1 enhanced immune function (CD4+/CD8+ T-cells, NK cells) and improved clinical outcomes in patients with CMV infection complicated by ARDS, demonstrating clinical efficacy for severe opportunistic viral infections.
Ji, S-M; Li, L-S; Sun, Q-Q; Chen, J-S; Sha, G-Z; Liu, Z-H · Clinical Trial
A1 beta-casein releases more beta-casomorphin-7 (BCM-7) during digestion than A2, with BCM-7 showing opioid, immunomodulatory, and GI effects that may explain the health differences attributed to A1 versus A2 milk consumption.
Kamiński, Stanisław; Cieslińska, Anna; Kostyra, Elzbieta · Review
Apelin knockout mice showed impaired cardiac contractility that worsened with aging and pressure overload, definitively establishing apelin as an essential cardiac peptide and a therapeutic target for heart failure and age-related cardiac decline.
Kuba, Keiji; Zhang, Liyong; Imai, Yumiko; Arab, Sara; Chen, Manyin; Maekawa, Yuichiro; Leschnik, Michael; Leibbrandt, Andreas; Markovic, Mato; Schwaighofer, Julia; Beetz, Nadine; Musialek, Renata; Neely, G Greg; Komnenovic, Vukoslav; Kolm, Ursula; Metzler, Bernhard; Ricci, Romeo; Hara, Hiromitsu; Meixner, Arabella; Nghiem, Mai; Chen, Xin; Dawood, Fayez; Wong, Kit Man; Sarao, Renu; Cukerman, Eva; Kimura, Akinori; Hein, Lutz; Thalhammer, Johann; Liu, Peter P; Penninger, Josef M · Animal Study
Antimicrobial peptides were repurposed as bacterial recognition molecules for biosensor-based detection, exploiting their selective membrane-binding properties for rapid pathogen identification — a diagnostic application beyond antimicrobial therapy.
Kulagina, Nadezhda V; Shaffer, Kara M; Ligler, Frances S; Taitt, Chris R · In Vitro