What are Glutathione Benefits? Uses & Side effects Explained What is glutathione? Know as the most important antioxidant in the body, glutathione is an essential antioxidant manufactured in all cells, but primarily in the liver. It is essential because it Glutathione is such a critical soldier in our line of defense that our bodies make it themselves. We even have mechanisms that recycle and reuse it. But what happens when our toxic The appeal of glutathione injections makes sense. Glutathione is one of the most important antioxidants your body produces, and levels drop as you age, making the idea of a quick boost tempting.