AAAAI Mast Cell Disorders Committee Work Group Report: Mast cell activation syndrome (MCAS) diagnosis and management Journal of Allergy and Clinical Immunology Mast cells are hypersensitive immune cells that release histamine and other inflammatory mediatorsoften in response to oxidative stress, environmental toxins, and immune imbalance. Many patients with MCAS have low levels of glutathione. If supplements seem to make you feel worse instead of better, you're not imagining it! Many of the supplements most commonly recommended for detox, gut health, or methylation can actually activate mast Glutathione MCCM Medical Cosmetics