nac glutathion bienfaits N-Acetyl Cysteine Premium to promote the production of glutathione Glutathione vs NAC: Key Differences,
Description
The concern is supplemental dosing , not glutathione itself

Choi JH, Stubblefield B, Cookson MR, et al

An oral loading dose of 140 mg/kg is given, followed by the administration of 70 mg/kg every 4 hours for 17 doses

doi: 10.1038/s41598-017-10442-7 15

This finding was not replicated in newer studies
