The global use of pharmaceuticals is constantly growing and leads to water contamination with xenobiotic compounds with a wide range of biological activity. Most pharmaceutical products that are widely used in medicine and veterinary medicine are constantly discharged into domestic wastewater in unchanged form or as active metabolites. These medications include hormones, antibiotics, analgesics, antidepressants, and antitumor medications. Treatment plants are not able to effectively remove these compounds from wastewater, which contributes to their migration to freshwater ecosystems. With a long half-life, pharmaceuticals can accumulate in the environment, reaching biologically active levels. The presence of pharmaceuticals in aquatic ecosystems can lead to unpredictable environmental consequences and reactions and can also have a negative impact on human health. In the Russian scientific literature, very little attention is paid to the problem of environmental pollution by pharmaceuticals. Therefore, this review article discusses the main sources of pharmaceuticals and their metabolites, the fate of these compounds in the aquatic environment, their impact on human health and aquatic biocenoses.