Impaired Homocysteine Metabolism and Atherothrombotic Disease Laboratory Investigation Homocysteine is an inflammatory amino acid that is produced as a byproduct of protein metabolism. Homocysteine induced injury to the arterial wall is one of the factors that can initiate the process of 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, Homocysteine Wikipedia Amazon.com: Allergy Research Group Homocysteine Plus Supplement with Setria Glutathione, Vitamin B Complex, Trimethylglycine, Vegetarian Capsules 90 Count : Health & Household