Brain Fog and Blue Moods Could Be Signs of a Glutathione Deficiency, Doctor Warns 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 Your body never lies. Your skin, your posture, your muscle tone, even the coating on your tonguethese are diagnostic tools. They're reflections of your internal biology. Skin mirrors the liver Mark Mark Hyman, MD Levels