What a peptide is
A peptide is a short chain of amino acids linked by peptide bonds, smaller than a full protein. The compounds in this catalog range from tripeptides (three amino acids, like GHK-Cu or KPV) to 40-plus-residue chains like the incretin agonists.
Sequence length and modifications (acetylation, PEGylation, fatty-acid chains) change how stable a peptide is and how long it lasts in solution, which is why storage windows differ so much across the catalog.
How research peptides are produced
Most are made by solid-phase peptide synthesis, then purified by high-performance liquid chromatography (HPLC) and identity-confirmed by mass spectrometry. The purity percentage on a COA is the HPLC figure: the fraction of the material that is the target peptide versus synthesis byproducts.
Lyophilization (freeze-drying) removes water so the peptide is shelf-stable as a powder until it is reconstituted for use.
Reading a product page
Molecular formula, molecular weight, and CAS number identify the exact compound. Purity and the lot-specific COA tell you what is actually in the vial you're buying. The evidence section describes published research and always labels the study type and population, so preclinical (in-vitro or animal) data is never presented as human-efficacy evidence.
