Markers of the functional state of the hepatobiliary system — enzymatic activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), levels of total and direct bilirubin, the value of thymol probe in the plasma of the diaphragm waves and the introduction of ω-3 PUFA were investigated. It has been found that the action of laser irradiation in blood plasma increases the enzymatic activities of aminotransferases and GGT, along with an increase in the level of total and direct bilirubin and thymol index. The corrective effect on the liver functional state is shown by ω-3 polyunsaturated fatty acids (PUFA). It has been established that the protective properties of ω-3 PUFAs depend on the scheme of their introduction. The highest hepatoprotective effect of ω-3 PUFAs is manifested under the conditions of their previous introduction to the action of laser irradiation, as evidenced by a decrease in hyperenzymemia ALT, AST, GGT, a decrease in total and direct bilirubin and thymol in plasma. The introduction of ω-3 PUFA after the end of the laser diode does not change the markers of the functional state of the liver in blood plasma compared with irradiated animals that were not injected with the studied lipophilic nutrients.