S-Acetyl Gluthione is not L-Glutathione!

I would love to read any published studies on Acetyl glutathione. Does anyone have the references and what is the dose? It appears all the references I have seen are not for Acetyl glutathione, but L-glutathione. 

Unfortunately, there have not been any human clinical studies in the public domain that have demonstrated that acetylglutathione is effective when taken orally. There have been studies in in-vitro and animal models using acetylglutathione which have been positive. These are limited to a few publications. At the same time, positive results have also been seen with glutathione in in-vitro and animal models in many publications. But, it is of utmost importance to demonstrate oral efficacy in a human clinical study.

A new study in the European Journal of Nutrition shows that oral glutathione supplements are available to the body and have a positive immune benefit. Great news after all the talk about glutathione being broken down in the gut and not available. This study shows that this is not entirely true. It is nice to see the research published!

Randomized controlled trial of oral glutathione supplementation on body stores of glutathione.

http://www.ncbi.nlm.nih.gov/pubmed/24791752

About the Study: 

·         Trial measured effect of glutathione supplementation at 250 mg/day and 1000 mg/day on glutathione levels in different blood components and exfoliated buccal mucosal cells over a six month period.¹

·         Subjects were 54 healthy adults (41 females/13 males), 28-72 years of age (mean=46.6 years).¹ 

·         Results of the study showed glutathione levels in the blood increased after one, three and six months vs. baseline at both doses.¹

·         At six months, mean glutathione levels increased 30-35 percent in erythrocytes, plasma, and lymphocytes, and 260 percent in buccal cells in the high dose group (P<0.05).

·         Glutathione levels increased 17 and 29 percent in blood and erythrocytes, respectively, in the low dose group (P<0.05).¹

·         A reduction in oxidative stress in both glutathione dose groups was indicated by decreases in the oxidized to reduced glutathione ratio in whole blood after 6 months.¹

·         According to the study, the effects of glutathione supplementation on the levels of the glutathione precursor cysteine in plasma and the activity of the rate-limiting glutathione biosynthetic enzyme GCL in erythrocytes were examined after the six-month study period.¹ No changes were observed in cyst(e)ine concentrations or GCL activity in any of the groups.¹