How Do Cells Produce Glutathione? Glutathione Reporter Homocysteine and methionine are key amino acids with a vital connection to glutathione one of your body's most important substances! Methionine is abundant in many foods, so protein isn't the culprit, Phase II Glutathione Conjugation Metabolism of Herbicides or Xenobiotics in Plants passel Catabolism of extracellular glutathione supplies cysteine to support tumours Nature