Well, its not a one-size-fits-all situation
It is possible to increase glutathione with good sleep, reducing stress, getting a good balanced diet, living an active lifestyle, avoiding drinking too much alcohol, and even trying some supplements like milk thistle (more information)
Li X, Zhou X, Ping X, Zhao X, Kang H, Zhang Y, et al
Vitamin B12 injections can contain cobalt, which can also cause an allergic reaction
To test this hypothesis, German Holstein cows were assigned to a control group (CON, n = 26) and an L-carnitine supplemented group (CAR, n = 27, rumen-protected L-carnitine product: 125 g/cow/d, corresponded to total L-carnitine intake: 25 g/cow/d, supplied with concentrate) and received an intravenous bolus injection of lipopolysaccharides (LPS, 0.5 g/kg body weight, E