Chondroitin is a naturally occurring substance that is a major component of cartilage, the tissue that cushions joints. It is commonly used as a dietary supplement, often in combination with glucosamine, with the aim of supporting joint health and, by extension, skeletal system function. The rationale for its use is based on the idea that supplementing with chondroitin may help maintain cartilage integrity, reduce pain, and improve joint function, particularly in individuals with osteoarthritis.

Scientific evidence regarding the effectiveness of chondroitin for supporting the skeletal system is mixed. Several meta-analyses and randomized controlled trials have investigated its effects, especially on osteoarthritis of the knee and hip. Some studies suggest a modest reduction in pain and improvement in function, while others show little to no benefit over placebo. The American College of Rheumatology and other expert bodies generally consider the evidence insufficient to make strong recommendations for its routine use, citing variability in study outcomes and potential publication bias.

Chondroitin is not considered a treatment for bone health per se (e.g., increasing bone density or preventing fractures), but its role in joint health does have indirect relevance to maintaining mobility and function in the skeletal system. Overall, while its use is widespread and supported by some scientific studies, the overall quality and consistency of evidence is moderate at best, which is reflected in the rating above.