Glutathione is a natural antioxidant your body makes, and it can influence melanin production which is why it's sometimes marketed for skin brightening. Oral supplements are mostly broken down in the Enhanced non enzymatic H2S generation extends lifespan and healthspan in male mice: Cell Metabolism Nebulized Glutathione for Smoke Inhalation Gordon Medical Associates Nebulization of glutathione and N Acetylcysteine as an adjuvant therapy for COVID 19 onset ScienceDirect Nebulization Timeless Life Clinic