Effects of Creatine and β-Alanine Co-Supplementation on Exercise Performance and Body Composition: A Systematic Review

Background/Objectives: Creatine and β-alanine are two widely used dietary supplements known to enhance exercise performance and improve body composition; however, less is known regarding the synergistic effects of combining the two supplements. Methods: A systematic search was conducted across PubMed/MEDLINE, Scopus, and Web of Science databases for randomized controlled trials (RCTs) published up to March 2025. Eligible studies included adult participants receiving creatine and β-alanine together compared to creatine or β-alanine alone for at least four weeks and assessed measures of exercise performance and/or body composition. Study quality was assessed using the Cochrane Risk of Bias tool. Results: A total of 7 randomized controlled trials (n = 263 participants; 231 males and 32 females) met the inclusion criteria. Collectively, the combination of creatine and β-alanine supplementation enhanced high-intensity exercise performance, particularly anaerobic power and repeated-bout performance, compared to creatine or β-alanine alone. Co-ingestion of creatine and β-alanine supplementation did not increase measures of maximal strength compared to creatine alone. The effects of creatine and β-alanine supplementation on body composition were equivocal, with one study reporting greater lean mass gains and fat mass reductions compared to creatine and β-alanine supplementation individually, while another found no significant improvements. Additionally, no significant improvements in aerobic endurance capacity (VO₂max, lactate threshold, or time to exhaustion) were observed from creatine and β-alanine supplementation co-ingestion. Conclusions: The combination of creatine and β-alanine supplementation may be effective for enhancing high-intensity exercise performance but has no greater effect on maximal strength, body composition, or measures of aerobic capacity compared to creatine or β-alanine alone.