Efficacy of Bioactive Collagen Peptide Compared to Glucosamine and Chondroitin Sulphate in Grade I-III Knee Osteoarthritis

Knee osteoarthritis is one of the leading causes of chronic pain, disability, and reduced quality of life among adults. Current non-surgical management focuses primarily on symptom relief through exercise, weight management, physical therapy, and analgesic medications. Although non-steroidal anti-inflammatory drugs (NSAIDs) remain widely used, their long-term use may be limited by gastrointestinal, cardiovascular, and renal adverse effects. As a result, there is increasing interest in nutraceutical therapies that may provide symptomatic relief with a more favorable safety profile.

Glucosamine and chondroitin sulphate are among the most commonly used symptomatic slow-acting agents for osteoarthritis, although published evidence regarding their effectiveness remains inconsistent. Bioactive collagen peptides have emerged as a potential alternative treatment because they may support cartilage metabolism and reduce symptoms associated with osteoarthritis. However, direct comparative evidence between bioactive collagen peptides and glucosamine-chondroitin sulphate remains limited.

This study is a prospective, single-center, open-label, parallel-group randomized controlled trial designed to compare the efficacy and safety of oral bioactive collagen peptide with oral glucosamine and chondroitin sulphate in adults with symptomatic Kellgren-Lawrence grade I to III knee osteoarthritis.

Participants are randomly assigned in a 1:1 ratio to receive either oral bioactive collagen peptide or oral glucosamine and chondroitin sulphate for 12 weeks. Clinical assessments are performed at baseline, 6 weeks, and 12 weeks. The study evaluates changes in knee pain, stiffness, physical function, and health-related quality of life using validated patient-reported outcome measures, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire. Safety is evaluated throughout the study by monitoring adverse events, medication compliance, and the use of rescue analgesics.

The primary objective is to determine whether bioactive collagen peptide provides clinical improvement comparable to glucosamine and chondroitin sulphate in reducing symptoms and improving function in patients with knee osteoarthritis. Secondary objectives include evaluating changes in health-related quality of life and comparing the safety and tolerability of both treatment strategies.

The findings of this study will provide comparative evidence regarding two commonly prescribed oral nutraceutical therapies for knee osteoarthritis and may help inform evidence-based conservative management of patients with early and moderate disease.

Inclusion criteria

• Adults aged 40 years and older.
• Clinical diagnosis of knee osteoarthritis according to the American College of Rheumatology (ACR) criteria.
• Radiographic Kellgren-Lawrence grade I, II, or III osteoarthritis in at least one knee.
• Willing and able to provide written informed consent.
• Willing to comply with the study protocol and attend all follow-up visits.

Exclusion criteria

• Inflammatory arthritis, including rheumatoid arthritis, systemic lupus erythematosus, spondyloarthropathy, or polymyalgia rheumatica.
• Post-traumatic osteoarthritis.
• Patients with hyperuricemia.
• Pregnancy or breastfeeding.
• Previous use of collagen peptide or glucosamine-chondroitin supplements before enrollment.
• Inability or unwillingness to comply with study procedures or complete follow-up.