In this paper, the influence of polyphenol extract from green walnuts on glutathione metabolism in the blood serum of breeding roosters was studied. To achieve this purpose, hydroalcoholic extract from green walnuts was used, with a total antioxidant activity of 548,37 mg gallic acid equivalent/100 gr. For the study were used two batches of roosters, of five animals in each batch, experimental and control. As a result of the research on the influence of metabolism, changes were obtained in the content of SH-groups, G-TP, G-S-T, as well as amino acids, which are part of the glutathione composition and which were studied in different biological fluids and reproductive cells. The basic mechanism of the central role of thiol-mediated redox control in cellular metabolism is the ability of thiol groups to reversibly change their redox state with subsequent changes in the conformational, catalytic or regulatory functions of the protein. The basis of cellular redox homeostasis, through which the redox state of thiol protein groups can be maintained, is the ratio between reduced glutathione (GSH) and oxidized glutathione (GSSG), present in most cells in millimolar concentrations [6, 9].