Impact of creatine supplementation alone or combined with exercise on inflammatory and clinical outcomes in chronic musculoskeletal pain treated in the rheumatological field: a systematic review.

Creatine supplementation has demonstrated ergogenic and anabolic effects in healthy and clinical populations. However, its potential therapeutic role in individuals with chronic musculoskeletal pain treated in rheumatological contexts remains unclear. The aim was to evaluate the efficacy and safety of creatine supplementation on pain, physical function/disability, quality of life, muscle strength, skeletal muscle mass, and inflammatory markers in people with chronic musculoskeletal pain usually treated from the rheumatological field. A systematic review was conducted following PRISMA guidelines. Searches were performed in MEDLINE, Web of Science, CINAHL, Scopus, and EMBASE up to July 2026. Eligible studies were randomized or nonrandomized clinical trials that provided creatine supplementation alone or in combination with exercise as a treatment compared to a control or placebo group. Eight studies (n = 189) were included, encompassing fibromyalgia, osteoarthritis, rheumatoid arthritis, and juvenile idiopathic arthritis. Creatine dosages varied from chronic low-dose to loading protocols (20 g/d, 2-5 g/d). Combined creatine plus resistance training may improve strength, skeletal muscle mass, and quality of life beyond exercise alone in osteoarthritis. Trials on fibromyalgia suggest an increase in muscle strength, but inconsistent effects on pain. Rheumatoid arthritis studies suggest gains in skeletal muscle mass and, in pilot studies, reduced disease activity. No major adverse events were reported. In conclusion, creatine supplementation alone may be insufficient to obtain clinical benefits, while combined with resistance exercise it could offer potential benefits for muscle strength, skeletal muscle mass and certain aspects of quality of life in these clinical conditions. However, evidence on pain and inflammation remains limited; Furthermore, the response across different clinical conditions is heterogeneous, highlighting the need for larger, high-quality trials.