A randomized crossover study in healthy volunteers showed that collagen hydrolysates from fish, porcine, and bovine sources all achieve relevant plasma concentrations of bioactive peptides regardless of animal origin or molecular weight.
All sources equally bioavailableFish, porcine, and bovine collagen hydrolysates achieved comparable plasma peptide concentrations
What the researchers found
All collagen hydrolysate sources (fish, porcine, bovine) at different molecular weights yielded comparable plasma concentrations of free and peptide-bound hydroxyproline, confirming bioavailability of intact collagen peptides.
Why it matters
The collagen supplement market is massive but bioavailability has been questioned. This study provides clinical evidence that collagen peptides survive digestion and enter the bloodstream — regardless of animal source — validating the supplement category's core premise.
The numbers in context
Fish, porcine, and bovine collagen sources tested; bovine at 2,000 and 5,000 Da molecular weights; single-dose crossover design; plasma amino acids and peptides measured.
How the study worked
Randomized, double-blind crossover clinical study in healthy volunteers. Single-dose bioavailability assessed by measuring plasma free and peptide-bound hydroxyproline and selected collagen peptides after intake of different CH sources.
Who was studied
Healthy adult volunteers
What this study cannot tell us
Single-dose study — chronic intake effects not assessed. Healthy volunteers only — absorption may differ in elderly or diseased populations. Plasma levels measured, but actual tissue delivery (skin, joints, bones) not confirmed. Small study size implied. Ideal plasma levels for biological effects are unknown.
How to read the evidence
Moderate evidence — well-designed randomized crossover clinical study in humans. However, small sample and single-dose design limit generalizability.
When this study was published
Published in 2024. Provides clinical pharmacokinetic data for an increasingly popular supplement category.
The bigger picture
This study addresses a fundamental question for the billion-dollar collagen supplement industry: do the peptides actually get into your blood? The answer is yes — and the source (fish, pig, cow) doesn't significantly affect absorption. This validates collagen supplementation as a legitimate delivery system for bioactive peptides.
Questions still open
- Do absorbed collagen peptides actually reach target tissues like skin and joints at functional concentrations?
- Does chronic collagen supplementation maintain or increase steady-state peptide levels?
- Is there a minimum molecular weight threshold that affects peptide bioavailability?
Common questions
Do collagen supplements actually get absorbed into your body?
Does it matter which type of collagen supplement I take?
Read the original research
Absorption of bioactive peptides following collagen hydrolysate intake: a randomized, double-blind crossover study in healthy individuals.
Frontiers in nutrition, 11, 1416643
Citation
Virgilio, Nicolina; Schön, Christiane; Mödinger, Yvonne; van der Steen, Bastiaan; Vleminckx, Sara; van Holthoon, Frédérique L; Kleinnijenhuis, Anne J; Silva, Catarina I F; Prawitt, Janne. (2024). Absorption of bioactive peptides following collagen hydrolysate intake: a randomized, double-blind crossover study in healthy individuals.. Frontiers in nutrition, 11, 1416643. https://doi.org/10.3389/fnut.2024.1416643