Harnden et al. 2023, citrulline and endurance performance meta-analysis

A systematic review and meta-analysis of 9 RCTs (n = 158) found no significant effect of citrulline supplementation on either time-to-exhaustion (pooled SMD = 0.03, 95% CI −0.27 to 0.33, P = 0.83) or time-to-completion (pooled SMD = −0.07, P = 0.67) in young healthy adults, with low between-study heterogeneity (I² = 0% for both outcomes). The authors concluded there is no significant endurance performance benefit of citrulline supplementation. Moderate evidence.