What the evidence says. Graded moderate: several RCTs at 40 mg/day show real reductions in WOMAC pain and improved knee function over 3-6 months, but trials are small (n=50-190), short, and largely funded by the ingredient maker, and one pooled analysis found no benefit on the Lequesne functional index. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)
What is UC-II (Undenatured Collagen)?
UC-II (Undenatured Collagen) (Undenatured type II collagen) is a joint and skin supplement used for ease knee osteoarthritis pain. NutriDex grades the human evidence as Moderate. UC-II is undenatured type II collagen sourced from chicken sternal cartilage, given at a tiny 40 mg dose. Unlike hydrolysed collagen, it is kept intact so its 3-D epitopes survive digestion and are thought to retrain joint-targeting immune cells (oral tolerance), dampening inflammation. In a 180-day, three-arm RCT (n=191) UC-II cut total WOMAC scores significantly more than placebo (p=0.002) and even outperformed glucosamine+chondroitin (p=0.04). A 90-day trial reported roughly a 33% WOMAC and 40% VAS-pain drop, and a study in healthy exercisers showed better knee extension and longer pain-free exertion. A 2023-2025 meta-analyses confirm meaningful WOMAC and VAS improvements, though function-index results were mixed. Limits matter: trials are small, run only 3-6 months, and most are industry-sponsored, so the effect is probably real but modest and not yet proven durable or head-to-head with drugs.
Purported Benefits
✓Ease knee osteoarthritis pain
✓Improve joint function & stiffness
✓Better knee range of motion
✓Exercise-related joint comfort
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
Outcome
Evidence
Effect
Studies
Ease knee osteoarthritis painMultiple RCTs and 2023-2025 meta-analyses show WOMAC/VAS pain reduction; trials small, short, mostly industry-funded.
40 mg/day of UC-II (about 10 mg bioactive undenatured type II collagen), taken once daily, ideally on an empty stomach.
Active Compounds
Undenatured (native) type II collagenTriple-helix collagen epitopes
Safety & Cautions
⚠
UC-II is well tolerated; trials report side effects no more often than placebo, with occasional mild GI upset or headache. It is derived from chicken cartilage, so avoid it if you have a chicken or egg allergy, and safety in pregnancy, breastfeeding and children is untested. No well-documented drug interactions exist, but because it acts on the immune system its effects are theoretically uncertain in people on immunosuppressants or with autoimmune disease; it is a supplement, not a substitute for prescribed osteoarthritis care. Educational only — always check with your doctor or pharmacist before combining UC-II (Undenatured Collagen) with any medicine.
Common questions about UC-II (Undenatured Collagen)
What is UC-II (Undenatured Collagen) used for?
UC-II (Undenatured Collagen) is most often taken for Ease knee osteoarthritis pain, Improve joint function & stiffness, Better knee range of motion, Exercise-related joint comfort. Low-dose chicken-cartilage collagen for knee osteoarthritis pain.
Does UC-II (Undenatured Collagen) work — what does the evidence say?
Moderate evidence. Several controlled trials; effects real but modest or context-dependent. UC-II is undenatured type II collagen sourced from chicken sternal cartilage, given at a tiny 40 mg dose. Unlike hydrolysed collagen, it is kept intact so its 3-D epitopes survive digestion and are thought to retrain joint-targeting immune cells (oral tolerance), dampening inflammation. In a 180-day, three-arm RCT (n=191) UC-II cut total WOMAC scores significantly more than placebo (p=0.002) and even outperformed glucosamine+chondroitin (p=0.04). A 90-day trial reported roughly a 33% WOMAC and 40% VAS-pain drop, and a study in healthy exercisers showed better knee extension and longer pain-free exertion. A 2023-2025 meta-analyses confirm meaningful WOMAC and VAS improvements, though function-index results were mixed. Limits matter: trials are small, run only 3-6 months, and most are industry-sponsored, so the effect is probably real but modest and not yet proven durable or head-to-head with drugs.
What is the typical dose of UC-II (Undenatured Collagen)?
40 mg/day of UC-II (about 10 mg bioactive undenatured type II collagen), taken once daily, ideally on an empty stomach.
Is UC-II (Undenatured Collagen) safe? Any cautions or side effects?
UC-II is well tolerated; trials report side effects no more often than placebo, with occasional mild GI upset or headache. It is derived from chicken cartilage, so avoid it if you have a chicken or egg allergy, and safety in pregnancy, breastfeeding and children is untested. No well-documented drug interactions exist, but because it acts on the immune system its effects are theoretically uncertain in people on immunosuppressants or with autoimmune disease; it is a supplement, not a substitute for prescribed osteoarthritis care.
How many studies support UC-II (Undenatured Collagen)?
NutriDex cites 8 sources for UC-II (Undenatured Collagen), graded "Moderate".
Cite this page
APA
Peh, D. (2026). UC-II (Undenatured Collagen) (Undenatured type II collagen): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/uc2-collagen
BibTeX
@misc{nutridex_uc2_collagen,
author = {Peh, Daryl},
title = {UC-II (Undenatured Collagen) (Undenatured type II collagen): Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/uc2-collagen},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.