is liposomal glutathione safe Glutathione: Benefits and Supplements

For severe B12 deficiency that maybe causing significant neurological symptoms, your doctor may use injectable form of B12 initially before transitioning to oral therapy

Ma PC, Jagadeeswaran R, Jagadeesh S, Tretiakova MS, Nallasura V, Fox EA, Hansen M, Schaefer E, Naoki K, Lader A, et al

Cysteine, the rate limiting amino acid in glutathione synthesis, is significantly decreased in ASD relative to control children, suggesting that glutathione synthesis is insufficient to maintain redox homeostasis (16)

GHK-Cu may be worth considering if the product matches your goal, fits your routine, gives clear directions, and provides quality testing