Glutathione (GSH, also called as reduced glutathione) is a tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes such as, glutathione reductase, glutathione peroxidases, peroxiredoxins. Glutathione S-transferases catalyse the conjugation of GSH via a sulfhydryl group to electrophilic centers on a wide variety of substrates in order to make the compounds more water-soluble. As a part of homeopathic product, glutathione is used for temporary relief of symptoms related to Free Radical Toxicity including tingling in hands and feet, mood changes, frequent colds, poor digestion, fatigue, and constipation. In addition, for temporary relief of pain in the back from urinating, constant urging and frequent urination, kidneys sensitive to pressure, and pain from back extending down the thigh. Glutathione is an important nutrient for brain function and loss of glutathione has been implicated in Parkinson's disease. In phase II of the clinical trial was investigated whether administration of either dose of glutathione, as a nasal spray, improves PD symptoms over time in a population of individuals with Parkinson's disease (PD). In addition in phase II of clinical trial was shown, that reduced glutathione, an ingredient of RayGel™, has been helpful in decreasing some radiation therapy side effects to the skin. Reduced glutathione plays a vital role in both making DNA and cell repair. Cystic fibrosis (CF) is the most common inherited disease among the Caucasian population with considerable morbidity and reduced life expectancy. Glutathione (GSH) represents the first-line defence of the lung against oxidative stress-induced cell injury. Therapeutic approaches with inhaled GSH could improve the reduced lung antioxidant capacity in order to counterbalance the oxidant stress linked to the chronic airway inflammation and bacterial infection.