Analgesic efficacy of collagen peptide in knee osteoarthritis: a meta-analysis of randomized controlled trials

Lin CR, Tsai SHL, Huang KY, Tsai PA, Chou H, Chang SH · Journal of Orthopaedic Surgery and Research

Pain SMD -0.58 (95% CI -0.98 to -0.18, p = 0.004) favouring collagen peptide, with I-squared 68%. Adverse-event risk did not differ (OR 1.66, 95% CI 0.99-2.78, p = 0.05). The authors declare no financial, commercial or other relationships. Worth setting beside the larger trial-sequential synthesis: this independent analysis reports a bigger pain effect from four trials than the 35-trial pooled estimate does, and grades all four of them at high risk of bias.

Population

Four randomized controlled trials of collagen peptide in knee osteoarthritis, 507 patients

Intervention

Collagen peptide

Comparator

Placebo

Limitations

Only four trials and 507 patients, all four rated high risk of bias by the authors themselves; GRADE certainty moderate for pain and very low for adverse events. Moderate heterogeneity (I-squared 68%) is unexplained — no subgroup analysis by dose, duration or collagen preparation is reported. Pain only; no function or imaging endpoint.