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Key takeaways
● Molecular weight continuum: native collagen (~300 kDa) → gelatin (20–250 kDa) → hydrolysed peptides (3–6 kDa) (1).
● Bone broth delivers roughly 0.6–1.0 g of collagen per cup (1). Matching a 10 g supplement dose means 10–17 cups daily — impractical.
● Gelatin gels; hydrolysed collagen does not. The kitchen test.
● Gelatin has one niche where it beats hydrolysed collagen: the Shaw 2017 pre-training protocol for tendon collagen synthesis used gelatin (2).
● For supplement-scale doses: hydrolysed peptides are what trials use and what the evidence base supports.
● Bone broth is a legitimate food, not a practical supplement substitute.
Quick answer
These are three forms of the same molecule at different degrees of processing. Native collagen in food (whole meat, chicken skin) is huge (~300 kDa) and largely digested to amino acids. Gelatin is partially denatured collagen with medium chains (20–250 kDa) that gels when cooled — good for tendon synthesis around exercise, less absorbable than hydrolysed peptides. Bone broth delivers dietary collagen in a food matrix at ~0.6–1.0 g per cup — a legitimate food but impractical as a supplement substitute (10–17 cups daily to match a 10 g scoop). Hydrolysed collagen peptides at 3–6 kDa are what supplement trials use and what the trial-observed clinical effects are built on. Enjoy bone broth as food; use hydrolysed peptides for supplement doses; consider gelatin specifically for pre-training tendon work.
The molecular weight continuum
Understanding the differences between these three forms starts with molecular weight, because that determines what actually reaches your bloodstream.
Native collagen (~285–300 kDa)
The collagen inside your body — and inside any piece of meat, skin, or connective tissue — exists as a triple helix of three long protein chains wound together into a rope-like structure. Each triple helix molecule weighs roughly 285–300 kilodaltons. This is enormous by protein standards, and far too large to absorb intact from the digestive tract (1). Native collagen in food is broken down over hours by acidic gastric digestion and small-intestine peptidases, releasing individual amino acids that absorb and join the general amino acid pool. The yield of intact bioactive dipeptides — the specific signalling molecules that give collagen its supplement-observed effects — is low from native collagen because most is broken all the way down before absorption.
Gelatin (20–250 kDa)
Gelatin is what happens when you take collagen and denature the triple helix by heat, acid, or alkali, but stop short of full enzymatic hydrolysis. The three chains separate but remain relatively long — typically 20–250 kDa. Gelatin dissolves in hot water and gels on cooling (this is the kitchen test that distinguishes it from hydrolysed collagen, which does not gel). Bioavailability of intact bioactive dipeptides from gelatin is better than from native food collagen but lower than from hydrolysed peptides.
Hydrolysed collagen peptides (3–6 kDa)
The final step is enzymatic hydrolysis using bacterial proteases under controlled temperature and pH conditions. This breaks the long chains into short peptide fragments in the 3–6 kDa range — small enough to dissolve in cold water and to absorb efficiently across the intestinal wall as intact peptide chains (3). The bioactive Pro-Hyp and Hyp-Gly dipeptides that drive the trial-observed clinical effects (skin, joint, bone) arrive at their target tissues in meaningful concentrations at gram-scale doses of hydrolysed peptides. This is what supplement brands sell and what almost all modern trial evidence uses.
Bone broth — the practical numbers
Bone broth is dietary collagen delivered in a whole-food matrix. Simmering bones and connective tissue in water for hours releases collagen (which becomes gelatin on cooling), amino acids, and small quantities of minerals into the liquid. Bone broth is a legitimate culinary food with real amino acid content and a cultural heritage across many cuisines from around the world.
The quantitative reality is where the substitution argument breaks down. A well-made bone broth contains roughly 0.6–1.0 g of collagen per cup (1). To match a 10 g supplement scoop you would need approximately 10–17 cups daily — impractical for most people and expensive whether homemade or bought. A 2019 analysis directly compared bone broth to supplemental collagen sources for the amino acid concentrations relevant to collagen synthesis; the paper explicitly concluded that bone broth is unlikely to provide reliable concentrations of collagen precursors comparable to supplement forms used in collagen research (4).
Two additional considerations. First, bone broth delivers collagen predominantly in its higher-molecular-weight forms — closer to native collagen and gelatin than to hydrolysed peptides. Even matching the raw collagen amount would not reproduce the bioactive dipeptide yield of hydrolysed supplement doses. Second, bone broth may contain measurable heavy metal content depending on source, particularly lead from the bones themselves. A 2017 analysis found variable but sometimes concerning heavy metal concentrations in commercial and homemade bone broths (5).
The right positioning: enjoy bone broth as a food you like. Do not think of it as a dose-equivalent alternative to a hydrolysed collagen supplement. It is delicious and nutritious food; it is not practical supplement dosing.
Gelatin — the one niche where it beats hydrolysed
For most goals, hydrolysed collagen outperforms gelatin because of superior bioactive dipeptide absorption. But one specific context flips this: the Shaw 2017 pre-training tendon protocol used gelatin, not hydrolysed collagen.
The Shaw 2017 trial from Keith Baar's laboratory showed that 15 g of vitamin-C-enriched gelatin taken about one hour before intermittent resistance exercise significantly increased circulating markers of collagen synthesis in an engineered-ligament model (2). The dose worked. Whether hydrolysed collagen would have performed comparably in the same protocol is not directly tested — but the trial that established the pre-training tendon-synthesis protocol used gelatin specifically.
Practical implication for athletes and tendon rehabilitation: if you are following the Shaw 2017 protocol strictly, gelatin (with vitamin C) is what the trial evidence directly supports. Hydrolysed collagen at similar doses is a reasonable substitute mechanistically, but the direct evidence is for gelatin. For all other indications — skin, joints, bone, general recovery — hydrolysed collagen has the clear evidence advantage.
The kitchen test — how to tell them apart
A useful practical distinction: dissolve a scoop of your product in cold water, then refrigerate.
● If it gels into a firm, jelly-like consistency: it is gelatin, not hydrolysed collagen. Perfectly fine for cooking and for the Shaw 2017 tendon protocol; less absorbable for other outcomes.
● If it stays liquid at fridge temperature: it is hydrolysed collagen. The peptide chains are too short to form a gel network.
This test does not tell you about molecular weight distribution within the hydrolysed range (2–3 kDa vs 5–6 kDa), which requires the product's Certificate of Analysis to confirm. But it distinguishes gelatin from hydrolysed collagen definitively.
Practical positioning — which one when
● For evidence-anchored supplement doses (skin, joint, bone, general collagen benefits): hydrolysed collagen peptides at 5–15 g/day depending on indication. This is what trial evidence supports.
● For pre-training tendon synthesis specifically: gelatin (or hydrolysed collagen) at 10–15 g with vitamin C, one hour before training. Shaw 2017 protocol (2).
● For culinary enjoyment and general dietary contribution: bone broth is a legitimate food. Do not treat it as a supplement replacement.
● For cooking applications (jellies, thickened sauces, marshmallows, gummies): gelatin is the functional choice. Culinary gelatin is not typically used at supplement doses.
● For readers who cannot tolerate powdered supplements or who prefer whole-food approaches: bone broth alongside general adequate protein intake is a legitimate but modest-effect approach.
The homemade gelatin option
A niche consideration: some readers make their own high-collagen preparations by slow-cooking bone-in cuts (oxtail, beef shank, chicken thighs with skin and bones) and consuming the collagen-rich broth or reduced sauce. This delivers collagen and gelatin in a food matrix at somewhat higher concentrations than commercial bone broth if the reduction is aggressive.
Honest assessment: it is enjoyable cooking and delivers real amino acids. Achieving a supplement-comparable dose of bioactive peptides through home cooking alone remains impractical without also consuming impractically large volumes. Do it for the food; do not treat it as a supplement substitute.
What we still don't know
● Whether hydrolysed collagen would perform equally to gelatin in the Shaw 2017 pre-training tendon-synthesis protocol. Not directly tested.
● Whether specific bone broth preparation methods (long-cook vs pressure cook, specific bones) meaningfully affect collagen or heavy metal content.
● Whether high-quality bone broth consumed at large volumes produces measurable clinical outcomes comparable to supplement doses. Trials of bone broth as supplement equivalent are essentially absent.
● Whether combining bone broth with hydrolysed collagen produces additive benefits. Not tested.
Bottom line
Hydrolysed collagen, gelatin, and bone broth are three forms of the same molecule at different degrees of processing. Native collagen and gelatin are much larger molecules than hydrolysed peptides and are less efficiently absorbed as intact bioactive dipeptides — the specific signalling substrate that drives supplement-observed clinical effects. Bone broth delivers roughly 0.6–1.0 g of collagen per cup — a legitimate food but impractical as a supplement substitute (10–17 cups daily to match a 10 g scoop). Gelatin has one niche where it directly beats hydrolysed collagen: the Shaw 2017 pre-training tendon-synthesis protocol used gelatin, and reproducing the exact evidence base means using gelatin. For all other supplement indications — skin, joint, bone, general — hydrolysed collagen peptides are what trial evidence supports. Enjoy bone broth as food; use hydrolysed peptides for supplement doses. See our hydrolysed vs non-hydrolysed article for the broader mechanism discussion.
Frequently asked questions
Is bone broth as good as collagen supplements?
No, at practical intake volumes. Bone broth delivers roughly 0.6–1.0 g of collagen per cup, so matching a 10 g supplement means 10–17 cups daily (4). Bone broth is a legitimate food; it is not a practical supplement substitute.
Is gelatin the same as collagen?
Related but distinct. Gelatin is collagen that has been denatured but only partially broken down — chains of 20–250 kDa. Gelatin gels when cooled; hydrolysed collagen does not.
Can I make my own hydrolysed collagen at home?
No, not practically. Hydrolysing collagen requires proteolytic enzymes under controlled temperature and pH conditions. Slow cooking produces gelatin, not fully hydrolysed peptides. Achieving supplement-comparable bioactive dipeptide concentrations through home cooking is not feasible.
Which is best for tendon repair?
Gelatin — specifically, 15 g of vitamin-C-enriched gelatin taken one hour before training — is what Shaw 2017 established (2). Hydrolysed collagen at similar doses is a mechanistically reasonable alternative but the direct evidence used gelatin.
Is bone broth healthier than collagen powder?
Bone broth is a whole food with additional nutritional value (minerals, other proteins, culinary satisfaction). Hydrolysed collagen is a concentrated supplement dose. Neither is universally healthier — they serve different purposes.
Does gelatin contain the same peptides as hydrolysed collagen?
Same molecular family, longer chains. Gelatin will produce Pro-Hyp and Hyp-Gly during digestion, but the yield of intact bioactive dipeptides reaching the bloodstream is lower than from pre-hydrolysed peptides.
Can I use gelatin sheets or powder as a collagen supplement?
Yes, though the bioactive dipeptide absorption is lower per gram than from hydrolysed peptides. For general supplement purposes, hydrolysed collagen is more efficient. For the Shaw 2017 pre-training tendon protocol specifically, gelatin has direct evidence support.
Does cooked chicken skin give me collagen?
Yes, some — chicken skin contains collagen (Type I and III), and cooking produces some gelatin. The amounts and bioavailability are modest compared to supplement doses. Enjoy it as food; do not rely on it for supplement-scale collagen intake.
References
1. León-López A, Morales-Peñaloza A, Martínez-Juárez VM, et al.. Hydrolyzed collagen — sources and applications. Molecules 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6891674/
2. Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr 2017. https://pubmed.ncbi.nlm.nih.gov/27852613/
3. Iwai K, Hasegawa T, Taguchi Y, et al.. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates. J Agric Food Chem 2005. https://pubmed.ncbi.nlm.nih.gov/16076145/
4. Alcock RD, Shaw GC, Burke LM. Bone broth unlikely to provide reliable concentrations of collagen precursors compared with supplemental sources of collagen used in collagen research. Int J Sport Nutr Exerc Metab 2019. https://pubmed.ncbi.nlm.nih.gov/30859848/
5. Hsu DJ, Lee CW, Tsai WC, Chien YC. Essential and toxic metals in animal bone broths. Food Nutr Res 2017. https://pubmed.ncbi.nlm.nih.gov/28932174/