NAC does raise glutathione synthesis over days to weeks, but acute dosing (6001,200mg) for hangover shows inconsistent results
Exclusion criteria were self-reported history of autoimmune diseases, chronic mental or neurological disorders, recurrent infections, substance abuse, previous brain surgery, and endotracheal or orotracheal intubation during COVID-19 treatment
Glutathione Injections Focuses on: Whole-skin glow, patchy tone
Mol Ther 2006;14:857-65
If you are expecting the overnight approach, this may not be the right approach
The MHRA have spent time during COVID alongside the ASA (Advertising Standards Agency) warning people who sell B12 injections direct to the public through beauty salons and the like that they absolutely must not tell those they advertise to, what B12 injections will do or what they can help with