Fundamentals
Fundamentals: 4 articles from Peptides Facts. Evidence-led reference on research peptides.
Reading a Peptide Sequence: Direction, Codes, Fragments and Modifications
A peptide sequence is a specification; a peptide name usually is not. The conventions that make a sequence readable — direction, numbering, two symbol sets, fragment ranges and modification notation — are few, fixed, and worth learning once.
L-Carnitine Is Not a Peptide: What It Does and What the Evidence Supports
Carnitine is a single small molecule of about 161 daltons that sits in peptide catalogues for commercial reasons rather than chemical ones. Its role in fatty acid transport is textbook biochemistry; the fat-loss claim built on top of that role is a separate question with a much weaker answer.
Why Most Peptides Are Not Orally Bioavailable
The gastrointestinal tract is a protein-digestion system, and a swallowed peptide is its intended substrate rather than an unlucky bystander. Five barriers stand between the mouth and the circulation, and unmodified peptides clear all five at well under 1%.
Peptide or Protein: Where the Boundary Sits, and Who Decides
Chemically the two are the same class of molecule. The line between them is drawn by convention, by folding behaviour, by how the molecule is manufactured — and, in the United States, at exactly 40 residues by statute.