# References — Research Peptide Fundamentals Literature — Peptide Batteries > The aggregated citation list for the Peptide Batteries research digest: peer-reviewed sources on GHK-Cu, MOTS-c, retatrutide, and tirzepatide, with DOIs and PubMed links. Every source cited across the four compound pages, the comparison, and the FAQ, gathered in one place. ## References The list below aggregates every source cited across the four compound pages, the comparison page, and the FAQ — GHK-Cu, MOTS-c, retatrutide, and tirzepatide. Each entry gives authors, title, journal, and year, with a DOI and a PubMed or PubMed Central link where available. A citation is listed once and referenced by its number throughout the site. Where a source is a review or structural/mechanistic study rather than a clinical trial, it is cited as such — the distinction matters for weighing what a given number actually demonstrates. ## References [1] Mortazavi SM, Mohammadi Vadoud SA, Moghimi HR. Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective. BioImpacts. 2025;15:30071. https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/ [2] Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences. 2018;19(7):1987. https://pmc.ncbi.nlm.nih.gov/articles/PMC6073405/ [3] Lee WJ, Sim HB, Jang YH, Lee SJ, Kim DW, Yim SH. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth. Annals of Dermatology. 2016;28(4):438-443. https://pmc.ncbi.nlm.nih.gov/articles/PMC4969472/ [4] Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International. 2015;2015:648108. https://pmc.ncbi.nlm.nih.gov/articles/PMC4508379/ [5] Hostynek JJ, Dreher F, Maibach HI. Human skin penetration of a copper tripeptide in vitro as a function of skin layer. Inflammation Research. 2011;60(1):79-86. https://pmc.ncbi.nlm.nih.gov/articles/PMC3016279/ [6] Kumagai H, Kim SJ, Miller B, et al. MOTS-c modulates skeletal muscle function by directly binding and activating CK2. iScience. 2024;27(11):111212. https://pubmed.ncbi.nlm.nih.gov/39559755/ [7] Bolignano D, Greco M, Presta P, Duni A, et al. The Mitochondrial-Derived Peptide MOTS-c May Refine Mortality and Cardiovascular Risk Prediction in Chronic Hemodialysis Patients: A Multicenter Cohort Study. Blood Purification. 2024;53(10):824-837. https://pubmed.ncbi.nlm.nih.gov/39111290/ [8] Wan W, Zhang L, Lin Y, Rao X, Wang X, Hua F, Ying J. Mitochondria-derived peptide MOTS-c: effects and mechanisms related to stress, metabolism and aging. Journal of Translational Medicine. 2023;21(1):36. https://pubmed.ncbi.nlm.nih.gov/36670507/ [9] Reynolds JC, Lai RW, Woodhead JST, Joly JH, Mitchell CJ, Cameron-Smith D, Lu R, Cohen P, Graham NA, Benayoun BA, Merry TL, Lee C. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nature Communications. 2021;12(1):470. https://pubmed.ncbi.nlm.nih.gov/33473109/ [10] Kim KH, Son JM, Benayoun BA, Lee C. The Mitochondrial-Encoded Peptide MOTS-c Translocates to the Nucleus to Regulate Nuclear Gene Expression in Response to Metabolic Stress. Cell Metabolism. 2018;28(3):516-524.e7. https://pubmed.ncbi.nlm.nih.gov/29983246/ [11] Lee C, Zeng J, Drew BG, Sallam T, Martin-Montalvo A, Wan J, Kim SJ, Mehta H, Hevener AL, de Cabo R, Cohen P. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism. 2015;21(3):443-454. https://pubmed.ncbi.nlm.nih.gov/25738459/ [12] Pham T, Taberner A, Hickey A, Han JC. Mitochondria-derived peptide MOTS-c restores mitochondrial respiration in type 2 diabetic heart. Frontiers in Physiology. 2025;16:1602271. https://pubmed.ncbi.nlm.nih.gov/40661667/ [13] Katsi V, Koutsopoulos G, Fragoulis C, Dimitriadis K, Tsioufis K. Retatrutide-A Game Changer in Obesity Pharmacotherapy. Biomolecules. 2025;15:796. https://pmc.ncbi.nlm.nih.gov/articles/PMC12190491/ [14] Li W, Zhou Q, Cong Z, Yuan Q, Li W, Zhao F, Xu HE, Zhao LH, Yang D, Wang MW. Structural insights into the triple agonism at GLP-1R, GIPR and GCGR manifested by retatrutide. Cell Discovery. 2024;10:77. https://pmc.ncbi.nlm.nih.gov/articles/PMC11255275/ [15] Sanyal AJ, Kaplan LM, Frias JP, Brouwers B, Wu Q, Thomas MK, Harris C, Schloot NC, Du Y, Mather KJ, Haupt A, Hartman ML. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nature Medicine. 2024;30:2037-2048. https://pmc.ncbi.nlm.nih.gov/articles/PMC11271400/ [16] Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. https://pubmed.ncbi.nlm.nih.gov/37366315/ [17] Rosenstock J, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial. Lancet. 2023;402(10401):529-544. https://pubmed.ncbi.nlm.nih.gov/37385280/ [18] Aronne LJ, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025. https://pubmed.ncbi.nlm.nih.gov/40353578/ [19] Farzam K, Patel P. Tirzepatide (StatPearls). StatPearls [Internet], NCBI Bookshelf. 2024. https://www.ncbi.nlm.nih.gov/books/NBK585056/ [20] Zeng Q, et al. Safety issues of tirzepatide (pancreatitis and gallbladder or biliary disease) in type 2 diabetes and obesity: a systematic review and meta-analysis. Front Endocrinol (Lausanne). 2023. https://pubmed.ncbi.nlm.nih.gov/37908750/ [21] Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022. https://pubmed.ncbi.nlm.nih.gov/35658024/ [22] Frias JP, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med. 2021. https://pubmed.ncbi.nlm.nih.gov/34170647/ --- A data-forward digest of peptide research — effect sizes and study designs, reported as measured, never as a prescription.