 Glutathione, GSH, is a powerful antioxidant with the ability to protect cells from oxidative stress. It is present at high concentrations within cells and is capable of neutralizing free radicals and other harmful compounds. When levels of GSH are low, cells become vulnerable to oxidative damage leading to various diseases. There is therefore great interest in finding ways to increase cellular GSH levels. This review discusses several methods for doing so, including supplementation with GSH itself or its derivatives, activation of the nuclear factor erythritid II related factor II, NRF II, cysteine prodrugs, foods, and special diets. Each of these methods has its own advantages and disadvantages, but all have the potential to increase cellular GSH levels and thus reduce oxidative stress. This article was authored by Daniella Giustorini, Aldo Molzani, Isabella Daldon, and others.