Dimethylamine hydrochloride (N,N-Dimethylamine) is abundantly present in human urine. Main sources of urinary dimethylamine have been reported to include trimethylamine N-oxide, a common food component, and asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis. ADMA is excreted in the urine in part unmetabolized and in part after hydrolysis to dimethylamine by dimethylarginine dimethylaminohydrolase (DDAH).