Peptides 101
From zero to understanding: what peptides are, what the types mean (peptide, analog, fragment), and how to read your first monograph without getting pulled into hype.
Editorial introduction
A peptide is a short chain of amino acids — everything between two proteins. That is all they have in common. 'Peptide' is not a quality category but a size: insulin is a peptide, and so is an unapproved fragment of gastric juice. That is why Peptidify grades every entry through four separate dimensions — status, evidence, type and interest — instead of one magic score.
Start with molecular type: a peptide is a natural or synthetic sequence; an analog is a deliberately modified version (longer half-life, stronger or weaker effect); a fragment is a piece of a larger protein carrying part of its action. Type tells you what the molecule is — not whether it works in humans.
When reading your first monograph, keep the order: focused review first, then human evidence, then unknowns. If human evidence 'essentially does not exist', everything below it is context, not justification.
Reading list
- 01BPC-157fragment
Synthetic fragment of the gastric juice protective peptide (BPC), isolated from human gastric juice protein.
Clinical trialsLimited evidence - 02TB-500fragment
Synthetic fragment (region 17–23, LKKTETQ) of the natural peptide Thymosin Beta-4.
Research chemicalLimited evidence - 03GHK-Cupeptide
Natural copper-binding tripeptide present in plasma; declines with age.
Research chemicalModerate evidence - 04MOTS-cpeptide
Peptide encoded by mitochondrial DNA (12S rRNA region), a 'mitochondrial peptide' involved in metabolism.
Clinical trialsModerate evidence - 05Ipamorelinanalog
Synthetic pentapeptide growth hormone secretagogue (GHRP) of the fifth generation; derived from earlier GHRP peptides.
DiscontinuedLimited evidence