Safety assessment of S-Acetyl Glutathione for use in foods and dietary supplements.

S-Acetyl Glutathione (SAG) is a glutathione precursor used as a food or dietary ingredient in a bioavailable form to restore or maintain circulating glutathione (GSH) levels. GSH is a potent defense compound against oxidative stress and a key determinant of many other physiological functions. The safety of SAG supplementation was assessed in an in vitro bacterial reverse mutation assay, an in vitro micronucleus test, an acute oral toxicity study, and a repeated dose (13 week) toxicity study. The in vitro assays did not reveal any genotoxic or mutagenic activity. No mortality or morbidity resulted from the acute oral toxicity study (LD50 > 2000 mg/kg). Administration of SAG over 13 weeks was well tolerated and did not result in any neurobehavioral alterations or effects on locomotor activity, ophthalmology, hematology, coagulation, blood biochemistry, urinalysis, thyroid hormones or the male reproductive system. Mild increases noted in liver, kidney and spleen weights were non-adverse and within historical control ranges, and no treatment-related gross or histopathology findings were observed in any organs. As a result, the NOAEL was determined to be 1500 mg/kg/day, the highest dose tested. Therefore, the results of these toxicological studies support the safe use of SAG in foods or dietary supplements.