Used in biochemical research as a cell-permeable arginine analog to modulate nitric oxide synthase (NOS) activity. It helps in studying nitric oxide-dependent signaling pathways and can act as an inhibitor or substrate for NOS isoforms, depending on the cellular context. Also employed in metabolic studies involving phosphorylated guanidino compounds due to its structural similarity to endogenous phosphoarginine. Its ability to cross cell membranes makes it valuable for in vitro and in vivo experiments aimed at understanding cardiovascular regulation, immune response, and neuronal signaling.