The claimEvidence C · limited
Drinking collagen / bone broth replaces your own collagen
The evidence
Oral collagen is broken into amino acids in the gut, not shipped intact to skin or joints (Paul 2019); hydrolyzed peptides show a weak signal, but Myung 2025 found no effect in non-industry-funded studies — and bone broth's dose is a blind box.
The mechanism, in brief
The collagen you eat is not delivered intact to your face or your knees. It is a protein, and in the gut it is cut up by stomach acid and digestive enzymes like any other protein.
Sources (2)
- Paul, C., Leser, S., & Oesser, S. (2019). Significant amounts of functional collagen peptides can be incorporated in the diet while maintaining indispensable amino acid balance. Nutrients, 11(5), 1079.
- Virgilio, N., Schön, C., Mödinger, Y., van der Steen, B., Vleminckx, S., van Holthoon, F. L., et al. (2024). Absorption of bioactive peptides following collagen hydrolysate intake: a randomized, double-blind crossover study in healthy individuals. Frontiers in Nutrition, 11, 1416643. Pro-Hyp and Hyp-Gly dipeptides are absorbed intact and peak in blood 60-120 min after intake. Note: the id says 'skov' but the first author is Virgilio (id kept because content files cite it). Design: pilot randomised double-blind crossover in 6 healthy volunteers (3 women, 3 men), single 10 g doses of fish, porcine and two bovine collagen hydrolysates; free hydroxyproline uptake was comparable across sources and Pro-Hyp was the most abundant collagen peptide in blood. The 60-120 min peak is the authors' summary of earlier studies, which they call consistent with their curves (full text, PMC11325589).