Trace amines are endogenous amines that are present in vertebrate tissues or fluids at concentrations up to 100 ng/g tissue and selectively bind to one or more TAARs at these concentrations. The first trace amines described, B-phenylethylamine, tyramine, tryptamine, and p-octopamine (classical trace amines), show molecular similarities to the known monoamine neurotransmitters dopamine, epinephrine, norepinephrine, and serotonin. In addition to classical trace amines, their derivatives are described, as well as diamines and polyamines, which are found in the body of mammals, but their functions are not completely clear. Trace amines also enter the human body with food and are synthesized by the symbiotic intestinal microbiota. It is important to note that the content of trace amines in human tissues and model animals changes in some pathologies (schizophrenia, ADHD, ulcerative colitis, epilepsy, etc.), which undoubtedly deserves close attention from the point of view of new targets for psychopharmacology in these diseases.