Collagen | Hydrolyzed Collagen Peptides
LATIN NAME: Collagen
COMMON NAME: Hydrolyzed Collagen Peptides
Science & Biotechnology
The peptides are absorbed intact enough to matter. Prolyl-hydroxyproline and hydroxyprolyl-glycine cross the gut wall through the PepT1 transporter and appear in plasma within an hour or two, peaking at one to two hours. That much is settled; what the peptides do after that is not.
The working hypothesis is that circulating fragments act as signalling molecules, stimulating fibroblast proliferation and hyaluronic acid synthesis, and inhibiting matrix metalloproteinases. Dozens of randomised trials have been published since 2010, most with thirty to a hundred participants and many funded by manufacturers. Pooled analyses report small improvements in skin hydration and elasticity, and in joint pain scores, with wide confidence intervals. Absorption also depends on the peptide mix: chains shorter than a kilodalton pass more easily but may carry less biological signal.
Uses & Benefits
Typical doses are 2.5 to 10 grams a day, taken with vitamin C, which is a cofactor for the enzymes that hydroxylate proline and stabilise the helix. Marine collagen is popular for taste and for religious constraints; bovine has more type I and type III.
The dark circle claim on this page needs a plain answer. Periorbital darkening comes from visible vessels under thin skin, from pigment, or from the shadow of a tear trough, and no oral collagen trial has measured it as an endpoint. What helps is sleep, iron status, sun protection and, for pigment, topical agents. Collagen is safe for most people, with fish allergy the main exception.
Our Take
A well-characterised protein with modest, real effects on skin and joints, sold with claims it cannot support; buy on dose and molecular weight, not on the picture on the tub.
Plant Profile
Collagen is not a plant and has no growing season. It is the structural protein of skin, tendon, bone and blood vessel wall, built as a triple helix of three peptide chains, each about a thousand amino acids long and unusually rich in glycine, proline and hydroxyproline.
What is sold as collagen peptide or hydrolysed collagen is that helix taken apart. Hides, split skin and fish skin are treated with alkali or acid, gelatinised, then digested with enzymes such as alcalase or pepsin into fragments of two to five kilodaltons. The powder dissolves in water and has almost no taste.
Growing from Seed
There is no seed, so the equivalent step is the production chain. Raw material is limed or degreased, extracted into gelatin at 60 to 90°C, then hydrolysed at a controlled pH and temperature, filtered through carbon, concentrated and spray-dried. Every stage changes the molecular weight, and molecular weight is what the label rarely states.
For a buyer, four things are worth checking: the declared peptide weight rather than the scoop size, the source species, a stated molecular weight below five kilodaltons, and a batch analysis for heavy metals, which is a real issue in fish skin from polluted water. Collagen is not vegan, and no plant protein substitutes for it.
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