Collagen supplementation for knee health, particularly in the context of weak knees or joint discomfort, has gained attention due to its role as a primary structural protein in cartilage, tendons, and ligaments. Several randomized controlled trials and meta-analyses have evaluated the efficacy of collagen hydrolysate or peptides in individuals with joint pain or osteoarthritis, including the knees. These studies generally suggest that collagen supplementation can lead to modest improvements in joint pain and function, especially in those with mild to moderate symptoms or those at risk of joint degeneration (e.g., athletes, older adults).

Meta-analyses published in reputable journals (e.g., Current Medical Research and Opinion, 2018; International Orthopaedics, 2021) have concluded that oral collagen supplements are associated with reduced joint pain, improved mobility, and potentially slowed progression of osteoarthritis. Proposed mechanisms include increased synthesis of cartilage matrix components and anti-inflammatory effects.

However, while the evidence is promising and supports traditional beliefs about collagen’s benefits for connective tissues, the effect size is generally modest and not all studies show significant benefits. The quality of evidence is moderate, with some studies limited by small sample sizes or industry funding. Nevertheless, the cumulative data justify the use of collagen for supporting knee health, particularly for mild joint weakness or discomfort.