Peptide
A peptide is a short chain of amino acids — the same building blocks that make up proteins — joined together in a set order. Proteins are long chains; peptides are the short ones, usually under about fifty links.
Where the word comes from
Peptide comes from the Greek peptós, meaning “digested.” The name fits: early chemists studied these short chains as the pieces proteins break into during digestion. The word was coined in the early 1900s, during Emil Fischer’s work on how amino acids join together — the link between two of them is still called the peptide bond.
What it means here
The order of the amino acids is called the sequence, and the sequence decides the peptide’s shape. Shape decides what a peptide can bind to inside a cell, which is why researchers care about it. The body makes thousands of its own peptides as chemical signals, and labs can build the same chains synthetically so they can be studied under controlled conditions. Most of the compounds in our catalog are peptides of this kind, sold as research material with the sequence and analytical data stated for each one.
Words you’ll see together
- sequence — the exact order of amino acids in the chain
- residue — one amino acid link once it is part of a chain
- peptide bond — the chemical link that joins two amino acids
- synthetic — built in a lab rather than taken from a living source
- analog — a peptide with a deliberately changed sequence, made for study
- fragment — a shorter piece cut from a longer natural sequence
Related terms
- Amino acid — the individual building block a peptide chain is made of
- Receptor — the cell protein a peptide’s shape lets it bind to
- Molecular weight — the measured mass of the whole chain, used to confirm identity
Where it appears in our catalog
- What research peptides are — the plain-language overview page
- BPC-157 — a short synthetic peptide, one of the most studied in the catalog
- Semax — a short peptide studied in nervous-system research models
- Find Your Peptide quiz — a guided way to browse the peptide catalog by research topic
References
- Renke G, Chinellato L (2026). Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions. Int J Mol Sci 27(9):3890. PMID 42123471 · DOI 10.3390/ijms27093890
- Artemis Labs, What research peptides are
