# References — Research Peptide Fundamentals Literature — Topical Peptides

> The aggregated citation list for the Topical Peptides research fundamentals digest: peer-reviewed sources on GHK-Cu, semaglutide, and thymosin alpha-1, with DOIs and PubMed links.

Every source cited across the three peptide pages and the comparison, gathered in one place.

## References

The list below aggregates the cited literature across all three peptides on this desk — GHK-Cu, semaglutide, and thymosin alpha-1. Each entry gives authors, title, journal, and year, with a DOI and a PubMed link where available. A citation is listed once and referred to by its number throughout the site.

## 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] Pickart L. The human tri-peptide GHK and tissue remodeling. Journal of Biomaterials Science, Polymer Edition. 2008;19(8):969-988. https://pubmed.ncbi.nlm.nih.gov/18644225/
[7] Maquart FX, Pickart L, Laurent M, Gillery P, Monboisse JC, Borel JP. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Letters. 1988;238(2):343-346. https://pubmed.ncbi.nlm.nih.gov/3169264/
[8] Aronne LJ, et al. (SURMOUNT-5 Investigators). Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025. https://pubmed.ncbi.nlm.nih.gov/40353578/
[9] Perkovic V, et al. (FLOW Trial Committees and Investigators). Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes. N Engl J Med. 2024. https://pubmed.ncbi.nlm.nih.gov/38785209/
[10] Lincoff AM, et al. (SELECT Trial Investigators). Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. N Engl J Med. 2023. https://pubmed.ncbi.nlm.nih.gov/37952131/
[11] Wilding JPH, et al. (STEP 1 Study Group). Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021. https://pubmed.ncbi.nlm.nih.gov/33567185/
[12] Smits MM, Van Raalte DH. Safety of Semaglutide. Front Endocrinol (Lausanne). 2021. https://pubmed.ncbi.nlm.nih.gov/34305810/
[13] Wu J, Pei F, Zhou L, et al. The efficacy and safety of thymosin alpha1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial. BMJ. 2025. https://pubmed.ncbi.nlm.nih.gov/39814420/
[14] Dominari A, Hathaway Iii D, Pandav K, et al. Thymosin alpha 1: A comprehensive review of the literature. World J Virol. 2020. https://pubmed.ncbi.nlm.nih.gov/33362999/
[15] Liu Y, Pan Y, Hu Z, et al. Thymosin Alpha 1 Reduces the Mortality of Severe Coronavirus Disease 2019 by Restoration of Lymphocytopenia and Reversion of Exhausted T Cells. Clin Infect Dis. 2020. https://pubmed.ncbi.nlm.nih.gov/32442287/
[16] Costantini C, Bellet MM, Pariano M, et al. A Reappraisal of Thymosin Alpha1 in Cancer Therapy. Front Oncol. 2019. https://pubmed.ncbi.nlm.nih.gov/31555601/
[17] Wu J, Zhou L, Liu J, et al. The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial. Crit Care. 2013. https://pubmed.ncbi.nlm.nih.gov/23327199/

---

A literary field guide to how research peptides reach the body — built on citations, not prescriptions, and never a recommended dose.