Longer Lifespans and Better Health with Glutathione: Taking the Confusion Out of the Master Antioxidant WholeFoods Magazine Selenocysteine muscle pain ** **A lack of selenium cause muscle pain mechanism of action.** Selenium exerts its biological functions via molecules called selenoproteins which contain the amino acid cysteine with Characterization and structural analysis of human selenium dependent glutathione peroxidase 4 mutant expressed in Escherichia coli ScienceDirect Role of Selenium and Vitamin E in Maintaining Healthy Muscles Glutathione peroxidase 4: a new player in neurodegeneration? Molecular Psychiatry 9.41 Selenoproteins Nutrition Flexbook