This systematic review and meta-analysis investigates the effects of branched-chain amino acid (BCAA) supplementation on muscle damage biomarkers and muscle soreness after exercise-induced muscle damage (EIMD). The study included 18 randomized controlled trials, with 13 of high quality and five of acceptable quality. BCAA supplementation significantly reduced creatine kinase (CK) levels immediately (Hedges' g = −0.44, p = 0.006) and 72 hours (Hedges' g = −0.99, p = 0.002) post-EIMD but not at 24, 48, or 96 hours. It also significantly reduced delayed onset of muscle soreness (DOMS) at 24 (Hedges' g = −1.34, p < 0.001), 48 (Hedges' g = −1.75, p < 0.001), 72 (Hedges' g = −1.82, p < 0.001), and 96 hours (Hedges' g = −0.82, p = 0.008) post-EIMD but not immediately. No significant effect was found on lactate dehydrogenase (LDH) levels at any time point. Meta-regression analyses indicated that higher daily and total dosages of BCAA, and longer supplementation periods, were associated with greater beneficial effects on CK levels at 48 hours and on DOMS at 24 hours. The study concludes that BCAA supplementation can reduce CK levels and DOMS after EIMD, with longer supplementation periods and higher dosages potentially enhancing these effects.This systematic review and meta-analysis investigates the effects of branched-chain amino acid (BCAA) supplementation on muscle damage biomarkers and muscle soreness after exercise-induced muscle damage (EIMD). The study included 18 randomized controlled trials, with 13 of high quality and five of acceptable quality. BCAA supplementation significantly reduced creatine kinase (CK) levels immediately (Hedges' g = −0.44, p = 0.006) and 72 hours (Hedges' g = −0.99, p = 0.002) post-EIMD but not at 24, 48, or 96 hours. It also significantly reduced delayed onset of muscle soreness (DOMS) at 24 (Hedges' g = −1.34, p < 0.001), 48 (Hedges' g = −1.75, p < 0.001), 72 (Hedges' g = −1.82, p < 0.001), and 96 hours (Hedges' g = −0.82, p = 0.008) post-EIMD but not immediately. No significant effect was found on lactate dehydrogenase (LDH) levels at any time point. Meta-regression analyses indicated that higher daily and total dosages of BCAA, and longer supplementation periods, were associated with greater beneficial effects on CK levels at 48 hours and on DOMS at 24 hours. The study concludes that BCAA supplementation can reduce CK levels and DOMS after EIMD, with longer supplementation periods and higher dosages potentially enhancing these effects.