Understanding collagen

Through dietary supplements and functional foods, collagen peptides are designed to support multiple health benefits, in particular beauty-from-within (skin health), mobility (joint health) and sports activities, and more broadly active living and healthy ageing (longevity).

GPO is a tripeptide composed of three amino acids, glycine (G), proline (P) and hydroxyproline (O). It is highly bioavailable, with good resistance to digestion and efficient absorption into the bloodstream, especially through peptide transporters such as PEPT1. GPO is among the most documented bioactive collagen tripeptides, one of the main active forms of hydroxyproline, and also a precursor of the highly bioactive dipeptides PO and OG. Animal collagen contains only low levels of GPO sequences, generally resulting in less than 1% GPO in conventional collagen peptides.

After ingestion, collagen peptides are further digested and hydrolyzed, and are partially absorbed into the bloodstream. They reach target tissues, where they act as biological signals, i.e. they stimulate specific cellular responses. In particular, bioactive di- and tripeptides containing hydroxyproline, such as GPO, can stimulate cells involved in collagen production, including skin fibroblasts and joint chondrocytes, helping support collagen synthesis and tissue maintenance. However, their exact mechanisms of action remain unclear and involve multiple biological pathways.

Collagen peptides have conventionally been extracted from animal tissues, primarily bovine, porcine, poultry and, more recently, marine (fish) sources.
However, these origins are not necessarily associated with specific peptide compositions or superior efficacy. They mainly reflect specific market demands, specifically regarding ethical considerations and perceived food safety. For example, bovine collagen is particularly popular in the United States, while marine collagen is often preferred in France and Europe.

The high daily doses required for conventional collagen peptides can create significant inconveniences for consumers. They are typically consumed as powders dissolved in drinks or incorporated into functional foods, or as multiple large capsules.
These doses can be difficult to take over time, affecting regular consumption and ultimately product effectiveness. At such doses, collagen peptides often have an unpleasant taste that can become tiresome for consumers, as can the strong flavorings sometimes used to mask it. Digestive discomfort, such as bloating and nausea, is also sometimes reported. In addition, collagen peptides derived from fish are allergens.
To overcome these challenges, some manufacturers use lower doses of collagen peptides in supplements or functional foods, however resulting in reduced effectiveness.

Recombinant collagen peptides are produced using genetically engineered cells, primarily through precision fermentation for food applications, whereas other applications may use mammalian cells.
Today, only a few companies are active in the food ingredient market, compared with a larger number in cosmetic and medical applications.
These first-generation recombinant collagen ingredients lack hydroxyproline and therefore do not contain bioactive tripeptides such as GPO. This limits their potential efficacy and requires high daily doses.These doses can be difficult to take over time, affecting regular consumption and ultimately product effectiveness. At such doses, collagen peptides often have an unpleasant taste that can become tiresome for consumers, as can the strong flavorings sometimes used to mask it. Digestive discomfort, such as bloating and nausea, is also sometimes reported. In addition, collagen peptides derived from fish are allergens.
To overcome these challenges, some manufacturers use lower doses of collagen peptides in supplements or functional foods, however resulting in reduced effectiveness.

Vegan collagen alternatives are primarily plant protein hydrolysates, which are not collagen peptides as they lack hydroxyproline and glycine every three amino acids, and therefore do not contain highly bioactive tripeptides such as GPO.
Their mechanisms of action differ from those of conventional collagen peptides. They mainly provide proteins and amino acids for nutritional purposes, with limited stimulation of specific cellular responses. Their efficacy on collagen-related health benefits remains limited, and they require high daily doses. Other alternatives include collagen boosters, such as vitamin C, zinc, copper and polyphenols, which may support endogenous collagen production or help limit its degradation through different mechanisms. Combining them with collagen peptides could offer broader benefits, but the high daily doses required for conventional collagen peptides make such combinations challenging.