這種營養素組合更抗衰老！ 人體研究驗證增加體內穀胱甘肽的有效方法。

You only need NAC + glycine to make glutathione inside the body. The other one is placebo, not needed.

You can look up the journal. The title is "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".