On the other hand, vitamin B12 injections deliver the vitamin directly into your body through your muscles
6,7FDA warns against the use of injectable glutathione as a skin whitener because whitening is not an approved use,9 efficacy is not well-established, and there have been reported side effects(acute renal failure, severe drug reactions such as generalized morbilliform eruption with angioedema and urticaria, vasculitis, anaphylactic shock and many documented side effects based on studies on IV glutathione used as skin whitening).6,7,8, 12
Along with two other amino acids glutamine and glycine NAC is necessary to make and replenish glutathione
Total spot polarization improved in both groups, and total skin tone improvement was slightly greater in the glutathione supplement group than in the placebo group, although this difference did not reach statistical significance