Trimethylamine (or TMA) a tertiary amine, is synthesized by the action of microbial enzymes in humans. The decrease of TMA metabolism and excessive TMA excretion cause the disease trimethylaminuria and some other diseases associated with the abnormal level of TMA, e.g., obesity, diabetes, cardiovascular diseases. It was shown, that TMS is a full agonist of human trace amine-associated receptor 5, TAAR5. In addition, TMA is a precursor of N-oxide form, an emergent biomarker of human health that can lead to renal diseases, neurological disorders, and cancer.