Obesity is one of the biggest challenges in the modern world. It is an established risk factor in the development of a variety of metabolic conditions such as metabolic syndrome, diabetes mellitus, cardiovascular diseases and others. By its nature obesity is heterogeneous condition and a wide range of factors are included in its etiology. It has specific neurobiological base in which the system of rewards has an important biological role. In recent years growing body of literature demonstrated neurobiological and behavioral relationships between food intake, drug addiction and withdrawal syndrome [1][2][3].Directly involved in the sense of pleasure, оpioid receptors and endogenous opioid peptides are main "players" in functioning of reward and pleasure system. The results of numerous studies provided evidence of interaction between different subtypes of opioid receptors and systems that regulate energy balance. According to the results of recent studies, obesity is closely related to aberrations in opioidergic neurotransmission, thus, correlating with the changes in the number of opioid receptors in the brain. Recent data provided convincing evidence on participation of opioidergic neurotransmission in feeding behavior. In this regard, it is necessary to note that the number of opioid receptors in corpus striatum and thalamus and body mass index (BMI) are inversely related. In patients suffering from obesity elevated plasma concentrations of β-endorphin have been demonstrated. Moreover, opiate receptor antagonists prevented development of obesity in genetically obese experimental animals [4,5].Presumably, the failure of opioid receptors is the main reason of overeating as an attempt to compensate the lack of positive emotions. In this regard there is enough evidence, indicating the involvement of opioidergic neurotransmission in the regulation of nutritional practices and obesity. Whether abnormalities in the endogenous opioid system play a primary role in overfeeding and weight gain or represent one of the numerous biochemical consequences of this metabolic state is still unclear. Understanding the role of opioids mediating food reward and promoting the overconsumption of appetising food may provide insights into new approaches to prevent obesity. Dopaminergic receptor system has been given a leading role in regulation of reward and motivation system associated processes. Moreover, its functioning is closely interrelated with cognitive functions. Substantial data obtained recently argue in favor of participation of dopaminergic neurotransmission in nutritional practices [6]. Interestingly, it has been demonstrated, that the main regulators of hunger and satiety, such as ghrelin, leptin and insulin, which participate in development of feeding behavior development, affected the dopaminergic system [7]. Moreover, it is quite remarkable that proopiomelanocortin (POMC), the anorexigenic hypothalamic regulator of food uptake, simultaneously is the precursor of some endogenous opioid peptides. Substance P (SP), a memb...