Glutathione: What It Is, Why You Need It, How You Can Increase It The Amino Company Think You Know Glutathione? Think Again! Metagenics UK Because glutathione levels decline as you age, and glycine can help slow the glutathione slide, it's a good idea to keep your levels high by eating protein rich foods, like organic poultry, grass fed 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