GSH has five major functions

Antioxidant:
Antioxidant is a substance that neutralizes destructive free radicals; some are manufactured by the metabolic processes of the body, others are derived from foods, the air we breath, exercise, stress and disease.GSH is the most powerful Antioxidant occurring naturally in the cells of the body. Through its significant reducing power, GSH also makes major contributions to the recycling of other Antioxidant that have become oxidized. Healthy cells homeostatically oppose free radicals through the use of Antioxidant, of which GSH plays a significant role. The effectiveness of other Antioxidant like vitamins C and E depends on the availability of GSH.

Help Prevent Disease:
Oxidative related diseases: accelerated aging, cell destruction, causes damage to DNA cellular patterns which leads to cancer, arteriosclerosis, coronary artery disease, Parkinson’s disease, diseases of the immune system, diabetes, cataract formation, Alzheimer’s, macular degeneration, COPD, allergy/asthma, stroke.

Detoxification:
GSH also plays a main role in detoxification..primarily in Phase II Liver detox. It "binds" to many toxins by its sulfur molecules and aids in forming a complex which the body then rids itself of.

Immune System Support:
When the immune system responds to an invader, it releases a blitz of free radicals to aid in the offensive agent's demise. This could create damage to local tissue and your body, but GSH rallies around the area to quench the free radicals that are produced in excess.

Protection from Radiation:
A recent research article published in the journal Radiology states that “radiation from a single whole-body scan is equal to that from 100 mammograms and is similar to that received by survivors of the atomic bombings of Hiroshima and Nagasaki, Japan – about 1 mile from the explosions – according to radiation biologist, David J. Brenner of Columbia University. The radiation from one scan is enough to produce a tumor in one out of 1200 people, and for those who have annual scans the risk increases to one tumor in every 50 people. With inadequate intracellular GSH the risk is greatly increased.