Glutathione injections and oral supplements are different delivery methods
Although the liver produces it, every cell can produce glutathione
Glutathione also aids in detoxifying the body and prevents damage from toxin buildup
You can also get it from supplements, but most of it is broken down by enzymes in the gut into amino acids, such that only long-term use of large amounts (500 mg or more) appears to modestly raise glutathione levels
Kaur H, Ganguli D, Bachhawat AK (2012) Glutathione degradation by the alternative pathway (DUG pathway) in Saccharomyces cerevisiae is initiated by (Dug2p-Dug3p)2 complex, a novel glutamine amidotransferase (GATase) enzyme acting on glutathione
Glutathione is incredibly beneficial, but there are 3 things you should know about what to avoid when taking glutathione