That is a great question. We still don't have a quick and easy glutathione test, so the best way to tell if you are deficient in glutathione or need more glutathione in your cells is to ask yourself if you have a health concern that is impacted on a cellular level. If the answer is yes, then there is a good chance that you may be deficient in glutathione and may benefit from raising your glutathione. Here's why.
First of all, the Physician's Desk Reference listing for Immunocal, a clinically proven glutathione booster, says this about glutathione deficient states:
"Glutathione deficiency states include, but are not limited to: HIV/AIDS, chemical and infectious hepatitis, prostate and other cancers, cataracts, Alzheimer's,Parkinsons , chronic obstructive pulmonary disease, asthma, radiation poisoning, malnutritive states, arduous physical stress, aging, and has been associated with sub-optimal immune response."
So if you deal with any of these conditions, there is a good chance you may be deficient in glutathione. Additionally, note this recent medical study:
"Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and as a result, disturbances in GSH homeostasis are implicated in the etiology and/or progression of a number of human diseases, including cancer, diseases of aging, cystic fibrosis, and cardiovascular, inflammatory, immune, metabolic, and neurodegenerative diseases.."- (Biol Chem. 2009 Mar; 390(3):191-214.)
So, as indicated by the above references, if you have a health concern that involves the health of your cells, which most health concerns do, then there is a good chance you will see improvement once you raise and sustain your glutathione levels.
You can order Immunocal to try it for yourself here.