The aim of research is assessing the effect of arsenic contained in water from centralized water supply sources on the parameters of the endocrine system and the biochemical profile of children and adults (ob-jects of study) living in a region with high arsenic content in drinking water. The quality of drinking water was assessed, the arsenic content in the blood, the concentration of hormones and biochemical parameters of the blood were studied. It has been established that the arsenic content in a number of water samples (4.3 mg/dm3) is 86 times higher than the MPC, while in 8% of adults and 19% of children from the ob-servation group an increased arsenic content in the blood was found. The main changes in the metabolic and biochemical contours in children who use water with a high content of arsenic are associated with a change in hepatic and renal markers, and in adults they are more changes (decreased albumin, increased bilirubin, increased not only creatinine, but also urinary acid), also in adults of the observation group, changes in a number of hormonal markers were found. Thus, the use of drinking water increased content of arsenic causes age-dependent changes in biochemical parameters and hormonal regulation, which is confirmed by the presence of causal relationships detected by adequate logistic regression models.