What is Glutathione?
Also known as gamma-glutamyl-cysteinyl-glycine (GSH), glutathione is a known antioxidant non-essential and thus, synthesized by the human body from glycine, L- glutamic acid and L-cysteine. In fact, all cells in the human body have the capability to produce such antioxidant. [1, 2]
A structure known as gamma-glutamyl-cysteinyl-glycine, or simply glutathione.
Acting as an antioxidant, glutathione prevents cellular damage caused by peroxides and free radicals . It is utilized in the repair and synthesis of DNA, prostaglandin and protein synthesis, in activating enzymes, and in transporting amino acids . It assists in neutralizing free radicals and reactive oxygen, and keeps the antioxidants Vitamin E and Ascorbic Acid in their reduced states . It regulates the nitric acid cycle, and also has a role in iron metabolism [6, 7].
Benefits of Glutathione Supplementation
There are many medical advantages in using glutathione. It is utilized in treating certain conditions, preventing a number of disorders and improving one’s lifestyle.
Glutathione has been coined as the “master oxidant”. It protects the human body from progressive aging. It salvages the antioxidants Vitamin E and Ascorbic Acid, preventing oxidative stress and further cell maturation. It also detoxifies the human body and controls the activity of immune cells. 
An illustration showing glutathione’s effect on aging.
GSH is also potentially effective in dealing with colitis. Studies have shown glutathione supplementation prevents damage to cells in the colon. 
It detoxifies and removes mercury and other heavy metals from the body. Glutathione affixes to mercury, chelating it and transporting it to the bile for disposal. Thus, it helps detoxify the nervous, reproductive and gastrointestinal systems. 
Studies have also shown the benefits of glutathione in controlling symptoms of autism. An eight week supplementation of the antioxidant had proven to improve the patients’ glutathione levels, hence, improving autistic manifestations. 
Glutathione supplementation with adequate exercise can also have an effect in the cardiovascular health. It may improve the antioxidant ability of the body and protect the heart from damage and further decrease in function caused by ischemic changes. 
Being one of its side effects, the skin whitening consequence of glutathione use has now become one of its main commercial uses. It reduces melanocytes, making the skin lighter and fairer. 
Other Medical Uses
This antioxidant is said to be effective in the treatment of glaucoma, cataracts, cystic fibrosis, Diabetes, Parkinson’s disease and even male infertility. It is also used for the prevention of Alzheimer’s disease, asthma, hepatitis, cancer, heart disease, osteoarthritis, and renal problems post-heart bypass surgery. 
Methods of Glutathione Administration
Oral glutathione may come as capsules, pills, tablets, and even in sublingual forms. These are usually called L-glutathione, reduced glutathione or GSH . However, these oral forms may only be absorbed in the bloodstream in a miniscule amount, hence are not effective in increasing the body’s glutathione levels.
These forms of glutathione are available in dosages from 50 to 500 mg capsules or tablets. However, researches have shown that circulating glutathione levels cannot be significantly increased by oral administration, particularly a single dose of 3 grams.Thus, dietary or oral glutathione cannot be a major determinant of glutathione levels in the blood. [15, 16, 17]
A photo illustrating oral tablets of glutathione.
Unlike oral glutathione, intravenous forms cannot be broken down by enzymes and gastric acid. Thus, it can substantially deliver the antioxidants and nutrients from the circulation to its end organ. 
An image of a patient having her dose of intravenous glutathione.
This route is a popular method of delivery used for complementary and alternative medicine therapy for Parkinson’s disease. It has been used clinically beginning the year 2005. Since then, it has been included in various studies to evaluate safety, tolerability and absorption of glutathione among patients with Parkinson’s. 
Inhaled glutathione is considered to be one of the most effective substances useful as antioxidant and is effective in the airways. Recent studies on nebulized glutathione have shown promise with inducing bronchoconstriction among patients with mild exacerbation and whose with partly controlled asthma. Researches on this substance had also been done among patients with emphysema, cystic fibrosis, and other acute sinus and lung concerns. 
Side Effects of Glutathione
Glutathione also has its adverse effects. It can cause simple symptoms such as abdominal pain and loose bowel movement, and serious complications like renal injury, Toxic Epidermal Necrolysis (TEN) and Steven Johnson Syndrome (SJS). 
Oral glutathione has been found to induce hypersensitivity reactions, characterized by maculopapular and urticarial form of rashes, and even zinc deficiency, upon long term use.
Although the intravenous forms have not had any observed adverse effects yet, nebulized forms of glutathione have been found to assist in sulfite formation. These sulfites consequently cause difficulty of breathing, hence are contraindicated to some patients with asthma… An issue which is still controversial, contradictory with some studies, and still for further research and investigation. [22, 23]
Thus, one should first weigh the pros and cons of glutathione use before intake. Furthermore, it would be of help if a consult to the physician would also be done prior to glutathione consumption.
- Wu, G. et al. Glutathione Metabolism and its Implications For Health. Journal of Nutrition. 2004 March; 134 (3): 489-92
- Pompella, A. The Changing Faces of Glutathione, A Cellular Protagonist. Biochemical Pharmacology. 2003; 66 (8): 1499-503.
- Scholz, R. et al. Mechanisms of Interaction of Vitamin E and Glutathione in the Protection Against Membrane Lipid Peroxidation. Annals in New York Academy of Science. 1989; 570:514-7.
- Clementi, E, et al. Phytochelatin Synthase Genes From Arabidopsis and the Yeast Schizosaccharomyces pombe. The Plant Cell. 1999; 11 (6): 11153-64.
- Chitranshu, K. Glutathione Revisited: A Vital Function in Iron Metabolism and Ancillary Role in Thiol-Redox Control. 2011; 30:2044-2056.
- Klatz, R. et al. The New Anti-Aging Revolution. 2003.
- Loguercio, C, et al. Glutathione Supplementation Improves Oxidative Damage in Experimental Colitis. Digestive Liver Diseases. 2003 Sept; 35 (9): 635-41.
- Kern, J, et al. A Clinical Trial of Glutathione Supplementation in Autism Spectrum Disorders. Medical Science Monitoring. 2011 Dec; 17 (12): 677-82.
- Ramires, PR, et al. Glutathione Supplementation and Training Increases Myocardial Resistance ti Ischemia-Reperfusion In Vivo. American Journal of Physiology. 2001 Aug; 281 (2): 679-88.
- Witschi, A, et al. The Systemic Availability of Oral Glutathione. European Journal of Clinical Pharmacology. 1992; 43(6): 667-9.
- Nutthavuth, A, et al. Glutathione As An Oral Whitening Agent: A Randomized, Double-Blind, Placebo-Controlled Study. Journal of Dermatological Treatment. 2010: 1-6
- Marrades, R, et al. Nebulized Glutathione induces Bronchoconstriction in Patient with mild Asthma. American Journal of Respiratory and Critical Care Medicine. 1997; 156 (20): 425-430