Effects of administration of unnatured collagen type II (UC-II) in knee osteoarthritis: a placebo-controlled, double-blind randomized clinical Trial

Purpose: Approximately 25% of people 55 and older have had knee pain, and about half of them have symptomatic knee osteoarthritis (OA). A new nutraceutical, undenatured collagen II (UC-II), has been studied in knee OA patients. The objective was to evaluate the effect of using undenatured type II collagen in subjects with knee OA. Methods: A double-blind, placebo-controlled, randomized controlled trial with 40 patients with grade I-III knee OA, randomized into collagen group (CG) and placebo collagen group (PCG). Pain, quality of life, functional capacity, muscle strength, flexibility, and joint mobility were evaluated at pre- and post-intervention. UC-II® was administered as a single daily oral dose of 40 mg for 90 days, as was placebo. Results: Pain decreased significantly at the end of the protocol in the CG. Bilateral quadriceps muscle strength was significantly higher in the CG participants in all reevaluations. Active and passive mobility of right knee flexion and extension increased in the CG. The CG showed greater functional gain than the PCG test at 30 days and at follow-up. WOMAC and Lequesne scores decreased significantly in all evaluations for CG compared to PCG. Conclusions: Administration of UC-II® improved pain, mobility, and function in participants with knee OA.