Understanding the Difference Between L Glutamine and Glutathione: What You Need to Know Cymbiotika CYMBIOTIKA L Glutamine vs L Glutathione: What's the Difference? H PROOF Glutathione is an antioxidant that's made up of the three amino acids glutamine, glycine, and cysteineall of which are rich in the mineral sulfur. The main functions of glutathione are to fend off Glutamine restores testicular glutathione dependent antioxidant defense and upregulates NO cGMP signaling in sleep deprivation induced reproductive dysfunction in rats ScienceDirect