Undenatured Type II Collagen
Evidence Fact Sheet
Undenatured type II collagen (UC-II) is a chicken-cartilage-derived supplement studied at ~40 mg/day for an oral immune-tolerance mechanism rather than as a collagen building block. Human RCTs report knee-joint and flexibility outcomes; reviews call for larger trials. DSHEA supplement (US); no EFSA health claim.
Also known as: UC-II · Native (undenatured) type II collagen · Chicken sternum cartilage collagen
Overview
Undenatured type II collagen (UC-II) is a native, triple-helix collagen sourced from chicken sternum cartilage and studied as an immunomodulatory ingredient — the proposed mechanism is oral immune tolerance via gut-associated lymphoid tissue (Peyer's patches) and regulatory T-cell induction, not the collagen-substrate pathway of hydrolyzed collagen peptides. The standardized research dose is 40 mg/day of UC-II (containing roughly 10 mg of bioactive undenatured type II collagen), distinct from gram-level hydrolyzed collagen and not interchangeable with it. Human studies use 90-180 day windows in knee osteoarthritis populations and 12-24 weeks for knee range-of-motion work in healthy, active adults. Regulatory status: a DSHEA dietary supplement in the US with self-determined GRAS and an NDI record; legal as a food supplement in the EU but with no EFSA-authorized health claim; permitted under ANVISA in Brazil and for conventional-food use in China. It is derived from poultry, so chicken/egg-allergy labeling caution applies.
Mechanism of Action
Oral immune tolerance via gut-associated lymphoid tissue (Peyer's patch) — research-context mechanism for the undenatured triple-helix form · Regulatory T-cell (Treg / FOXP3) induction and downregulation of autoreactive response to type II collagen (mechanistic, RA-context studies) · TGF-beta-mediated immunomodulation of the response to articular cartilage antigens · Proposed NF-kB signaling modulation linked to inflammatory-marker changes · Triple-helix native structure is hypothesized to be the determinant of the tolerance pathway (vs denatured/hydrolyzed forms)
Body systems: Musculoskeletal · Immune System · CONNECTIVE
Evidence-Based Benefits
Each benefit below is anchored to a specific PubMed-indexed study. Effect sizes, sample sizes, and p-values are reported as published; no values are inferred. Honest negatives and null results are kept alongside the positive findings, and disease-research populations are described as such — Undenatured Type II Collagen is not characterized as a treatment for any disease.
Knee Osteoarthritis Symptoms (WOMAC)
RCT supported- p = 0.002WOMAC vs placebo · 180d
- p = 0.04WOMAC vs glucosamine+chondroitin
In the largest UC-II knee-osteoarthritis RCT, 40 mg/day UC-II over 180 days produced a significantly greater reduction in overall WOMAC score than both placebo and glucosamine+chondroitin, with concordant pain, stiffness and physical-function subscale signals. The abstract reports significance levels rather than absolute WOMAC point changes.
Reported effect: the UC-II group demonstrated a significant reduction in overall WOMAC score compared to placebo (p = 0.002) and GC (p = 0.04)
“One hundred ninety one volunteers were randomized into three groups... daily dose of UC-II (40 mg), GC (1500 mg G & 1200 mg C), or placebo for a 180-day period... the UC-II group demonstrated a significant reduction in overall WOMAC score compared to placebo (p = 0.002) and GC (p = 0.04).”
Source: PMID 26822714 · Lugo 2016 · Nutr J
Head-To-Head vs Glucosamine + Chondroitin
RCT supported- 33% vs 14%WOMAC reduction · 90d
- 40% vs 15.4%VAS pain reduction
- 20% vs 6%Lequesne index reduction
In a separate knee-osteoarthritis trial comparing UC-II directly with glucosamine plus chondroitin over 90 days, UC-II produced larger percentage reductions in WOMAC, VAS pain and Lequesne functional index, reaching significance from baseline where the glucosamine+chondroitin arm did not. This trial reports percentage changes but no placebo arm and no sample size in the abstract.
Reported effect: treatment with UC-II reduced the WOMAC score by 33% as compared to 14% in G+C treated group after 90 days; UC-II treatment decreased VAS score by 40% after 90 days as compared to 15.4% in G+C treated group
“treatment with UC-II reduced the WOMAC score by 33% as compared to 14% in G+C treated group after 90 days... UC-II treatment decreased VAS score by 40% after 90 days as compared to 15.4% in G+C treated group... Treatment with UC-II reduced Lequesne's functional index score by 20% as compared to 6% in G+C treated group at the end of 90-day treatment.”
Source: PMID 19847319 · Crowley 2009 · Int J Med Sci
Knee Flexibility / Range of Motion in Healthy Adults
RCT supported- 96healthy subjects · 24 wk
- 3.23° vs 0.21°knee ROM flexion · p = 0.025
- 2.21°ROM extension gain · p = 0.0061
In a multicenter RCT of 96 healthy adults without diagnosed osteoarthritis, 40 mg/day UC-II for 24 weeks significantly increased knee range-of-motion flexion versus placebo and improved extension over time, with a larger flexion gain in the subgroup over 35 years old. This is a flexibility/function endpoint in healthy knees, not a disease outcome.
Reported effect: statistically significant increase in knee ROM flexion was observed in the undenatured collagen group versus the PLA group (3.23° vs. 0.21°; p = 0.025); an increase in knee ROM extension by 2.21° was observed over time in the undenatured collagen group (p = 0.0061)
“Ninety-six (n = 96, 20-55 years old) subjects... 40 mg of undenatured collagen (n = 48) supplementation daily for 24 weeks... a statistically significant increase in knee ROM flexion was observed in the undenatured collagen group versus the PLA group (3.23° vs. 0.21°; p = 0.025)... an increase in knee ROM extension by 2.21° was observed over time in the undenatured collagen group (p = 0.0061), while the PLA group showed a nonsignificant increase by 1.27°.”
Source: PMID 35377244 · Schön 2022 · J Integr Complement Med
Joint and Motor Function in Healthy Volunteers
RCT supported- 3.2 mg/dwater-soluble UC-II (NEXT-II)
A randomized, double-blind, placebo-controlled trial in healthy volunteers using a water-soluble undenatured type II collagen (NEXT-II, 3.2 mg/day) for 12 weeks reported significant improvements in knee flexion/flexible-angle range and in secondary measures (JKOM, knee/lower-back VAS, 10-meter walk, stair-climbing, JLEQ). The abstract describes direction of effect but reports no effect-size numbers or p-values, so no quantitative effect was extracted.
Effect size: this study reports the direction of the finding but does not state a specific numeric effect size, so none is given here rather than estimated.
“Fifty-eight participants (placebo = 28; NEXT-II® group = 30) completed the study... NEXT-II® (undenatured type II collagen 3.2 mg/d)... significant improvements in 'flexion' and 'flexible angle (range)'... significant improvements in JKOM, VAS for knee and lower back discomfort, 10-meter walking test, stair-climbing test, and JLEQ.”
Source: PMID 35512781 · Shiojima 2023 · J Am Nutr Assoc
Overall Evidence Synthesis (Narrative Review)
Emerging / indexed- 12 studiesreviewed · pre-clinical + clinical
- 40 mg dailydose characterized as safe
A 2025 narrative review synthesizing 12 studies concluded UC-II at 40 mg daily appears safe and efficacious in the short- and mid-term for reducing pain, improving function, range of motion and quality of life in knee osteoarthritis — while explicitly stating that larger, adequately powered, longer-follow-up trials are still needed before routine clinical use is justified. This is a review-level qualitative conclusion, not a pooled effect size.
Reported effect: UC-2 (40 mg daily) is safe and efficacious in the short- and mid-term, reducing inflammation and pain, and improving function, range of motion (ROM) and overall QoL
“Twelve studies (3 pre-clinical studies, 8 clinical studies and 1 study with both pre-clinical and clinical component) met our pre-defined search and inclusion criteria... UC-2 (40 mg daily) is safe and efficacious in the short- and mid-term, reducing inflammation and pain, and improving function, range of motion (ROM) and overall QoL... More adequately powered, prospective, multi-center, non-randomized and randomized controlled trials with longer follow-up are warranted to establish the long-term efficacy of UC-2 in knee OA patients and justify its routine clinical use.”
Source: PMID 40253594 · Gupta 2025 · Ann Med
Oral Immune Tolerance in Rheumatoid Arthritis (Mechanistic Limit)
Null / no benefit Emerging / indexed- SNP A-15,737genetic modifier of OT response
The rheumatoid-arthritis oral-tolerance pathway remains mechanistic and unresolved. A 2024 analysis examined why oral type II collagen tolerance responses vary, linking a genetic variant (SNP A-15,737) to the ability of type II collagen to suppress an inflammatory (IFN-gamma) response in RA cells — but the abstract reports no clinical primary-outcome effect size, sample size or significance level, so no efficacy number could be extracted. Type II collagen is not an established treatment for rheumatoid arthritis.
Effect size: this study reports the direction of the finding but does not state a specific numeric effect size, so none is given here rather than estimated.
“The SNP A-15,737 was found to associate with the ability of CII to suppress IFNγ production by α1(CII)-stimulated RA PBMC.”
Source: PMID 38897565 · Postlethwaite 2024 · Am J Med Sci
Dosage (research context · not a recommendation)
40 mg/day standardized UC-II (containing ~10 mg bioactive undenatured type II collagen); 90-180 day intervention windows in knee osteoarthritis RCTs (onset ~4-12 weeks); 12-24 weeks in healthy-knee range-of-motion RCTs. Distinct from hydrolyzed type II collagen, which is studied at gram-level doses (1-10 g/day) and is a different molecular form — UC-II data must not be extrapolated to hydrolyzed collagen.
Regulatory Status · 4 Markets
- US · FDA
- US FDA — DSHEA dietary supplement; structure/function claims permitted with mandatory disclaimer. UC-II (Lonza, formerly InterHealth) holds GRAS status (self-determined GRAS (Bioiberica Collavant n2 and others)) and a New Dietary Ingredient (NDI) notification record. Disease/treatment claims for osteoarthritis or rheumatoid arthritis are prohibited.
- EU · EFSA
- EU — legal to market as a food supplement under Directive 2002/46/EC; chicken-source type II collagen has a use history (not classified as Novel Food, though specific new extraction processes may trigger case-by-case evaluation). EFSA has NOT authorized any Article 13/14 health claim for type II collagen (no company application submitted); only ingredient-fact statements are permissible in the EU.
- CN · China
- Approved for conventional-food use in China (2016, National Health Commission) as undenatured type II collagen from chicken sternum cartilage; not classified as a New Food Raw Material (novel food).
- BR · ANVISA
- Brazil ANVISA — permitted dietary supplement (Suplemento Alimentar) under RDC 243/2018; the positive list (IN 28/2018 Anexo I, as amended by IN 76) includes the entry 'Colágeno de frango com colágeno tipo II não desnaturado.' Anexo III minimum effective dose 1.2 mg/day (>=19 yr); Anexo IV sets no explicit upper limit. Commercial UC-II dose of 40 mg/day is a market consensus (Lugo 2016), not a regulatory ceiling. Portuguese-language labeling and poultry-allergen consideration required.
Safety
Generally well tolerated in human RCTs at 40 mg/day for 90-180 days, with adverse-event rates comparable to placebo (Crowley 2009 PMID 19847319; Schön 2022 PMID 35377244); rarely mild, transient GI complaints (nausea, bloating) not significantly different from placebo. ALLERGEN: derived from chicken sternum cartilage (Gallus gallus domesticus) — individuals with chicken/poultry or egg-protein allergy should exercise caution and source must be labeled. No well-characterized drug interactions; individuals on immunosuppressant therapy may wish to consult a clinician given the proposed immune-tolerance mechanism. Insufficient safety data in pregnancy/lactation (not recommended) and in children/adolescents (treated as an unsuitable population given insufficient safety data).
Related
Goals: joint-bone
Lifestyles: senior-60-plus
References
PubMed-indexed citations anchoring the benefit findings above. Effect sizes are reported as published.
- PMID 26822714 · Lugo 2016 · Nutr J — Knee Osteoarthritis Symptoms (WOMAC)
- PMID 19847319 · Crowley 2009 · Int J Med Sci — Head-To-Head vs Glucosamine + Chondroitin
- PMID 35377244 · Schön 2022 · J Integr Complement Med — Knee Flexibility / Range of Motion in Healthy Adults
- PMID 35512781 · Shiojima 2023 · J Am Nutr Assoc — Joint and Motor Function in Healthy Volunteers
- PMID 40253594 · Gupta 2025 · Ann Med — Overall Evidence Synthesis (Narrative Review)
- PMID 38897565 · Postlethwaite 2024 · Am J Med Sci — Oral Immune Tolerance in Rheumatoid Arthritis (Mechanistic Limit)
Frequently Asked Questions
1. Is UC-II the same as hydrolyzed or regular collagen peptides?
No. UC-II is native, undenatured triple-helix type II collagen studied at a low ~40 mg/day dose for a proposed oral immune-tolerance mechanism, whereas hydrolyzed collagen is a denatured, gram-level building-block ingredient. They are different molecular forms, and the UC-II joint data described here should not be extrapolated to hydrolyzed collagen products.
2. What dose is used in the research?
Human trials standardize on 40 mg/day of UC-II (containing roughly 10 mg of bioactive undenatured collagen), used over 90-180 days in knee osteoarthritis populations and 12-24 weeks in healthy-knee range-of-motion studies. One healthy-volunteer trial used a different water-soluble form at 3.2 mg/day for 12 weeks.
3. Is the evidence settled?
Not fully. A 2025 narrative review of 12 studies described UC-II at 40 mg daily as safe and efficacious short- and mid-term, but explicitly called for larger, adequately powered, longer-follow-up trials. Several trials are sponsor-linked and some lack a placebo arm, and the rheumatoid-arthritis oral-tolerance pathway remains mechanistic with no efficacy effect size extractable from the cited analysis. No EFSA health claim has been authorized.
Last evidence review: 2026-06-13