Gelatin and Undenatured Type II Collagen
How gelatin, bone broth and undenatured type II collagen (UC-II) differ from collagen peptides, with what trials of 40 mg UC-II show and where evidence stops.
Content last updated . This page has not been medically reviewed.
Overview
Three products are often lumped together with collagen but are not the same: gelatin, bone broth, and undenatured type II collagen (often sold as UC-II). They differ in how they are processed, how much is taken, and what has been tested. The head-to-head of collagen peptides and gelatin is on Collagen peptides vs gelatin. The main guide is Collagen supplements.Gelatin
Gelatin is made by denaturing and partly breaking down collagen. Hydrolyzed collagen (collagen peptides) is made from the same raw materials, commonly pig or cow skin, and broken down further. [1] In the lab, hydrolyzed collagen can be made by starting from gelatin and treating it with enzymes. [1]I did not find trials in this review testing ordinary food gelatin for skin, joints or bone. For those uses, Proper evidence not found for gelatin itself; the trials on the collagen page tested hydrolyzed collagen.
Bone broth
Bone broth is a food made by simmering bones. A laboratory analysis found that standardized bone broth had less of the key collagen amino acids than a 20 g dose of collagen supplement used in research. [2] Amounts varied a lot between recipes, and café-prepared broths had the most. [2] The authors concluded it is unlikely to be a consistently reliable source of those building blocks. [2] Bone broth can still be a food you enjoy; the point is that the supplement research does not tell you what a cup does.Undenatured type II collagen (UC-II)
Undenatured type II collagen is derived from chicken sternum cartilage. [3] It is processed to keep its structure, and the proposed way it works is different from peptides: a review describes an immune-related mechanism called oral tolerance. [4] That is the review's account of how it works; the human trials above measured symptoms, not the mechanism.| Study | What it found | Evidence label |
|---|---|---|
| 191 people with knee osteoarthritis, 180 days, 40 mg UC-II vs placebo vs glucosamine plus chondroitin | UC-II improved overall symptom score compared with both comparators; safety outcomes did not differ. [3] | Promising but limited |
| 55 healthy people with exercise-related knee pain, 120 days, 40 mg | Better knee extension than placebo; well tolerated. [5] | Promising but limited |
| Review of 8 randomized trials, 243 people on UC-II | Better pain and function scores than placebo in early knee osteoarthritis; the authors said limited literature, with larger studies needed. [6] | Promising but limited |
| Review of 12 studies | Safe and effective at 40 mg a day in the short and mid-term, but longer trials are needed. [4] | Promising but limited |
An overview of osteoarthritis supplements found undenatured type II collagen had a clinically important effect on pain at medium term, although the quality of evidence across all supplements ranged from very low to high. [7] Several of the UC-II trials are small, so read the results as encouraging, not settled.
Study amounts and safety
The studies used 40 mg of UC-II daily, a tiny amount compared with several grams of collagen peptides. [3] This is a study amount, not a recommendation. UC-II and collagen peptides are different products, so their amounts cannot be compared. The trials reported no safety difference from placebo. [3] The sources did not cover autoimmune conditions, pregnancy, children, or drug interactions, so ask your clinician if any apply, and see How interactions work.Related
Collagen types and sources · Collagen for skin, joints and boneFrequently asked questions
Is gelatin the same as collagen?
Gelatin is partly broken-down collagen; hydrolyzed collagen is made from the same raw materials and broken down further. [1]
Does bone broth work like a collagen supplement?
One analysis suggests it is unlikely to provide reliable amounts of the key amino acids compared with collagen supplements used in research. [2]
What is UC-II and how much is used?
Undenatured type II collagen from chicken sternum cartilage; studies used 40 mg a day. [3]
Does UC-II work for knee osteoarthritis?
Small to mid-sized trials suggest less pain and better function in the short term; larger and longer studies are needed. [6]
References
- Al Hajj W, Salla M, Krayem M, et al. Hydrolyzed collagen: Exploring its applications in the food and beverage industries and assessing its impact on human health - A comprehensive review. Heliyon 2024. Read 2026-10-22.
- 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. Read 2026-10-22.
- Lugo JP, Saiyed ZM, Lane NE. Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study. Nutr J 2016. Read 2026-10-22.
- Gupta A, Maffulli N. Undenatured type II collagen for knee osteoarthritis. Ann Med 2025. Read 2026-10-22.
- Lugo JP, Saiyed ZM, Lau FC, et al. Undenatured type II collagen (UC-II) for joint support: a randomized, double-blind, placebo-controlled study in healthy volunteers. J Int Soc Sports Nutr 2013. Read 2026-10-22.
- Kumar P, Bansal P, Rajnish RK, et al. Efficacy of undenatured collagen in knee osteoarthritis: review of the literature with limited meta-analysis. Am J Transl Res 2023. Read 2026-10-22.
- Liu X, Machado GC, Eyles JP, Ravi V, Hunter DJ. Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis. Br J Sports Med 2018. Read 2026-10-22.