Lugo · Nutrition journal 2016 · multicenter randomized double-blind controlled trial · n=191

Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study.

Cited 169 times in the scientific literature.

Level 2 - randomized trial

Multicenter, double-blind, randomized, placebo- and active-controlled trial.

PubMed 26822714 · doi:10.1186/s12937-016-0130-8 · record verified 2026-08-29

What was done

In a multicenter, double-blind, randomized controlled trial, 191 adult volunteers with knee osteoarthritis were allocated to one of three daily oral interventions for 180 days: undenatured type II collagen (UC-II, 40 mg), glucosamine hydrochloride plus chondroitin sulfate (GC, 1500 mg glucosamine and 1200 mg chondroitin), or placebo. The primary endpoint was the change in total Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score from baseline to day 180. Secondary outcomes included WOMAC subscales (pain, stiffness, physical function), the Lequesne Functional Index (LFI), and a Visual Analog Scale (VAS) for pain, analyzed using modified intent-to-treat methods.

What was found

At day 180, total WOMAC score reduction was significantly greater in the UC-II group compared to placebo (p = 0.002) and GC (p = 0.04). UC-II also significantly improved WOMAC subscale scores compared to placebo: pain (p = 0.0003), stiffness (p = 0.004), and physical function (p = 0.007). Compared to GC, UC-II showed significant improvements in pain (p = 0.016) and stiffness (p = 0.044). Specific point estimates, mean differences, and standard deviations were not reported in the abstract. Safety and adverse event rates did not differ significantly between groups.

Why it matters

This study provides randomized controlled evidence that low-dose undenatured type II collagen can outperform both placebo and the standard combination of glucosamine and chondroitin for knee osteoarthritis symptom relief over 6 months.

Limits

The abstract reports only p-values without absolute scores, effect sizes, or confidence intervals. Findings for the secondary VAS and LFI endpoints are omitted from the abstract text. Structural disease progression (e.g., joint space narrowing via imaging) was not measured, and follow-up was limited to 180 days.

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