Quality Attributes and Documentation of Research-Grade Synthetic Peptides: A Grey-Literature Overview and Comparative Category Review (BPC-157, TB-500, GHK-Cu, Retatrutide and Reconstitution Supplies)

A non-peer-reviewed narrative overview (grey literature) of the analytical quality attributes, stability considerations and documentation practices relevant to research-use-only (RUO) synthetic peptides commonly supplied to laboratories, with a comparative category review of BPC-157, TB-500 / thymosin beta-4 fragments, GHK-Cu, retatrutide, MOTS-c, Semax/Selank, thymosin alpha-1 and bacteriostatic water as a reconstitution supply. It summarises public peer-reviewed and regulatory sources and proposes a supplier documentation checklist. No new experimental data are reported. The author is affiliated with a research-peptide supplier in Georgia (conflict of interest declared). Not medical advice; materials discussed are not for human or veterinary use.