Supplemental Citrulline Is More Efficient Than Arginine in Increasing Systemic Arginine Availability in Mice

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5368575/#:~:text=In%20contrast%2C%20citrulline%20supplementation%20not,arginine%20in%20increasing%20arginine%20availability.

Citrulline stimulates muscle protein synthesis, by reallocating ATP consumption to muscle protein synthesis

https://onlinelibrary.wiley.com/doi/full/10.1002/jcsm.12435  

Influence of L-citrulline and watermelon supplementation on vascular function and exercise performance.

https://www.ncbi.nlm.nih.gov/pubmed/27749691