Major regulatory agencies such as the FDA have given it the Generally Recognized As Safe (GRAS) designation
Breathing issues: In rare cases, one may experience difficulty in breathing due to glutathione
Clinical evidence consists of encouraging preclinical results and several early human trials demonstrating enhancements in fertility markers and outcomes, albeit with varying sample sizes and methodologies
PubMed: 24791752Clinical (RCT / meta-analysis) ref-2.Kumar P, Liu C, Suliburk J, Hsu JW, Muthupillai R, Jahoor F, Minard CG, Taffet GE, Sekhar RV Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial