Glycosaminoglycans (GAGs), such as chondroitin sulfate and hyaluronic acid, are frequently used in the support and management of cartilage damage, particularly in the context of osteoarthritis. Scientific validation for their use stems from both in vitro and in vivo studies, as well as clinical trials, though the strength of evidence varies depending on the specific compound and formulation. GAGs are key structural components of cartilage, contributing to its resilience and ability to retain water, and thus, their supplementation is hypothesized to help restore or maintain cartilage integrity.

Chondroitin sulfate has been the subject of numerous randomized controlled trials and meta-analyses. Some studies have reported modest improvements in pain and joint function in osteoarthritis patients, while others show minimal or no benefit compared to placebo. Hyaluronic acid, often administered via intra-articular injection, has also shown mixed results; some trials report symptomatic relief, while others find little difference from placebo. The variability in outcomes may be due to differences in study design, product quality, and patient populations.

Guidelines from major rheumatology organizations sometimes acknowledge the potential benefit of GAGs but often regard the evidence as limited or inconsistent. Overall, while there is a scientific rationale and some supportive evidence for the use of glycosaminoglycans in cartilage damage, the clinical benefits are generally considered to be modest and more research is needed to establish their efficacy conclusively.