Methylguanidine is primarily used in research settings to study its role as a uremic toxin in chronic kidney disease. It is often employed in laboratory experiments to investigate its effects on cellular functions and its potential contribution to complications associated with kidney failure, such as cardiovascular diseases. Additionally, methylguanidine serves as a biochemical marker in studies exploring metabolic pathways and toxin accumulation in various tissues. Its application extends to the development of therapeutic strategies aimed at mitigating the harmful effects of uremic toxins in patients with renal impairment.