Tripeptide / Tetrapeptide
Also known as: tripeptide · tetrapeptide · pentapeptide · oligopeptide
Short peptides named for their residue count — three (tri), four (tetra), five (penta) amino acids.
Peptides are frequently named by how many amino-acid residues they contain: a dipeptide has two, a tripeptide three, a tetrapeptide four, a pentapeptide five, and so on; the general term for a short chain is an oligopeptide.
Many well-studied research peptides are very short — GHK-Cu and KPV are tripeptides, Epitalon is a tetrapeptide, Ipamorelin is a pentapeptide. Short chains are easier to synthesise reproducibly and to characterise by mass spectrometry.
Longer chains (roughly 50+ residues) are conventionally called proteins rather than peptides, though the dividing line is not sharp.
RELATED TERMS
Amino Acid
The building-block molecules of peptides and proteins; each contributes one residue to the chain.
Peptide Bond
The covalent amide bond linking amino acids into a peptide chain — the defining structural feature of every peptide.
GHK-Cu
A copper-binding tripeptide (Gly-His-Lys) studied for collagen synthesis, skin remodelling and hair-follicle support.
Epitalon
A tetrapeptide (Ala-Glu-Asp-Gly) studied for telomerase activation, circadian regulation and longevity research.
KPV
A tripeptide (lysine-proline-valine) from the C-terminus of alpha-MSH, studied for anti-inflammatory and gut-calming effects.
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.