Glutathione History and Background
Glutathione was discovered in the year 1888. Glutathione is such a ubiquitous and versatile functioning molecule that shortly after its discovery in 1888 by J. de Rey-Pailhade, this7, 8, 9 small tripeptide molecule was deemed so important with so many vital functions that it was considered coincident with the "origin of life."
Sir Frederick Gowland Hopkins (1861-1947) of Cambridge University is also credited with a role in Glutathione's discovery and characterization and its name. (See Hopkins, FG and Dixon, M, J Biol Chem  54, 527-563). He received the Nobel Prize in 1929.
In many ways, glutathione is like a vitamin; glutathione has at least 15 functions, and there is a high turnover of glutathione in the body.
There is a constant turnover of GSH in the body, with the liver occupying a central position in this dynamic flux; turnover of GSH in normal liver, estimated in rodents and humans, approximates 20% per hour.10
Restoring the bodily levels of glutathione involved certain scientific challenges because of the chemical subtleties and technicalities presented by the amino acids involved in its synthesis, which synthesis process can only take place intracellularly. Glutathione is synthesized within every cell of the body.
Dr. Albert Crum, the founder of ProImmune®, understood that L-Cysteine is the most important part of that synthesis process. He also understood that owing to its unstable nature and oxidizability, L-Cysteine needs to be guided safely into bodily cells to participate in Glutathione synthesis. He proclaimed via his Patent that L-Cystine, which is made of two L-Cysteines bound together, is the optimal natural physiologic carrier of L-Cysteine until it passes the cell wall, whereupon the two L-Cysteines can immediately participate in the synthesis of Glutathione. Dr. Dean P. Jones, Director of the Emory University School of Medicine Biomarkers Laboratory, has discussed a cysteine/cystine shuttle in which cystine is transported into cells reduced and released as cysteine. Alternatively, plasma membrane oxydoreductases could use cellular reductives to reduce cystine to cysteine without transport.11
7 De Rey-Pailhade J. 1888a. Sur un corps d'origine organique hydrogénant le soufre 1 à froid. Comptes Rendus Hebdomadaire Séances de l'Académie de Sciences. 16:1683-4. Cited in Glutathione in the Nervous System, Ed. Christopher A. Shaw. Washington, DC, Taylor & Francis, Page 4.
8 De Rey-Pailhade J. 1888b. Nouvelle recherches physiologique sur la substance organize hydrogénant le soufre à froid. Comptes Rendus Hebdomadaire Séances de l'Académie de Sciences. 107:43-4. Cited inGlutathione in the Nervous System, Ed. Christopher A. Shaw. Washington, DC, Taylor & Francis, Page 4.
9 De Rey-Pailhade J. 1888. Bull.Soc Hist Nat Toulouse, 173(1888). Cited inGlutathione in the Nervous System, Ed. Christopher A. Shaw. Washington, DC, Taylor & Francis, Page 4.
10 Veterinary Clinics of North America: Small Animal Practice: Nutraceuticals and 5 other biologic therapies. (Ed. Lester Mandelker, DVM). January 2004, Volume 34 Number 1. Philadelphia, PA: Saunders an imprint of Elsevier, Inc, © 2004., page 84.
11 Jones, DP. "Extracellular Redox State: Refining the Definition of Oxidative Stress in Aging." Rejuvenation Research Volume 9, Number 2, 2006; pp. 169-80.