Glutathione is an indispensable component of the body's own redox and detoxification systems for breaking down radicals and other chemical pollutants. This textbook shows the current state of science and the study situation as well as the possibilities for the use of glutathione and its precursors in medical everyday life. On the one hand, it serves as a source for the understanding of the diverse effects of this substance and as an argumentation aid against unobjective criticism and, on the other, as an indispensable tool for the successful use of glutathione in clinical practice.