Glutathione (also called GSH) is produced naturally by the body and serves as a powerful antioxidant that strengthens the immune system and protects against oxidative stress. It also helps increase energy, reduces muscle and joint discomfort, improves mental focus and clarity, and even improves the look and feel of skin. The secret of its power is the sulfur (SH) chemical groups it contains. Sulfur is a sticky molecule that acts like fly paper to attract free radicals and toxins in the body to stick and trap them.