Deciding on a product for supplementing glutathione greatly depends on the reason why you want to supplement glutathione. Are your needs long term or short term? How important is cost? Are you interested in better athletic performance, general wellness, or support for a treatment such as chemotherapy or radiation? Ideally, the type of glutathione supplementation you choose should be safe, affordable and there should be clinical evidence that it actually is effective at increasing cellular glutathione levels in humans. Glutathione does its work inside the cells of the body, so a supplement should increase glutathione at the cellular level.
Many products can be eliminated from consideration because clinical evidence indicates that they do not work. Glutathione in capsule or tablet form is very common. However, many professionals feel that oral administration of glutathione is ineffective, commonly citing the studies done at the University of Bern and Emory University. One study demonstrated that rats are able to absorb oral glutathione. This goes to show that animal studies alone are not necessarily a reliable guide.
When glutathione is taken orally, very little reaches the bloodstream. There are other products that are probably more effective at delivering glutathione to the bloodstream. There are nasal, sublingual (under the tongue), dermal (patches), and even intravenous administrations. One oral product encloses reduced glutathione in microscopic packages called liposomes. There is not a great deal of clinical evidence that any of these methods increase cellular levels of glutathione. Even if that were the case, the long term use of a direct delivery method might pose problems. The body already has a complex system for managing glutathione involving production, recycling and a two stage negative feedback loop for regulating cellular glutathione levels. Forcing glutathione into the body is likely to disrupt the balance of this system.
Availability of the amino acid cysteine can limit the body’s production of glutathione. Therefore, the two most popular ways of making cysteine available for glutathione production are N-acetyl cysteine (also called NAC) and whey protein concentrate. Other compounds that are known to increase levels of glutathione include S-adenosylmethionine, alpha lipoic acid and silymarin or milk thistle. There are products that use combinations of these compounds. They generally include a cysteine donor such as NAC or whey protein in conjunction with the other compounds so as to provide support for all phases of glutathione metabolism.
The long term use of glutathione supplementation for purposes of general wellness or healthy aging deserves more study. At this time, results of any large scale studies of long term supplementation in a human populations have not been published. Some studies suggest that the use of N-acetyl cysteine for this purpose might be a problem since part of the NAC is converted to S-nitroso-N-acetylcysteine, abbreviated SNOAC. This compound might cause arterial problems such as pulmonary arterial hypertension.
Whey protein, on the other hand, is nothing more than milk protein. Fresh, raw milk is treated with citric acid (acid whey) or rennet (sweet whey). This causes the casein protein to curdle leaving the whey protein dissolved in the clear liquid that is left over. This clear liquid is called whey. The whey is filtered and dehydrated to a dry powdered concentrate. That is basically how whey powder products are produced. It is sterile and reputable companies generally have a scrupulous quality control process that insures a safe, pure, and consistent product. In addition to supplementing glutathione, whey protein is known to increase muscle mass. This may help offset sarcopenia, one of the conditions that contribute to Frailty Syndrome that is common to older persons.
There is a lot of variation of protein composition of whey powders. This affects glutathione supplementation output. A comparison of various protein powders can be found at http://www.rimkor7.com/best_protein.php.