UC-II Undenatured Type II Collagen for Knee Joint Flexibility: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Study

Schön C, Knaub K, Alt W, Durkee S, Saiyed Z, Juturu V · Journal of Integrative and Complementary Medicine

Knee range-of-motion flexion increased significantly versus placebo, with a larger effect in the over-35 subgroup (6.79 degrees vs 0.30). But read the extension result carefully: the 2.21 degree gain was a WITHIN-group change, and placebo also rose 1.27 degrees, so extension did not separate between groups. No pain outcome was reported at all.

Population

Healthy adults aged 20-55 with activity-related joint discomfort on a single-leg step-down test, no osteoarthritis

Intervention

40 mg undenatured type II collagen daily for 24 weeks

Comparator

Placebo

Limitations

Three authors are employees of Lonza Greenwood LLC, which owns UC-II. Healthy volunteers rather than osteoarthritis patients, and range of motion rather than pain or function. The headline age subgroup is a secondary analysis.