f glutathione Force Factor (Reduced) 500 mg every ingredient is meticulously tested for potency and purity Glutathione | FancyMeds

Fisetin, a natural flavonoid, attenuated DOX-mediated ferroptosis in vivo and in vitro by raising the contents of GSH and GPX4 and inhibiting the accumulation of MDA and iron in the heart of rats [92]

Additionally, BP may effectively increase safe mechanisms against skin dryness, oxidative damage caused by ultraviolet radiation, melanogenesis and inflammation have a role in a great variety of negative effects on human skin (139)

Avoid use in patients with known hypersensitivity to Glutathione or injection excipients

That is what their reference to "immunogenicity" means

[DOI] [PMC free article] [PubMed] [Google Scholar] 158.Lu H., Samanta D., Xiang L., Zhang H., Hu H., Chen I., Bullen J.W., Semenza G.L

doi: 10.1111/jfbc.13635 119