vitamin c or glutathione which is better C? for dark spots and dull skin while reducing oxidative stress that triggers discolouration Glutathione And Vitamin C Therapy:

Welsh JW, Seyedin SN, Allen PK, Hofstetter WL, Ajani JA, Chang JY, Gomez DR, Amini A, Swisher SG , Blum MA, Younes AI, Nguyen QN, Minsky BD, Erasmus JJ, Lee JH, Bhutani M, Komaki RU

When indicated, useful laboratory tests may include a complete blood count (CBC) to assess for anemia, comprehensive metabolic panel for electrolyte and kidney function, vitamin B12 , 25-hydroxyvitamin D , and iron studies (serum iron, ferritin, total iron-binding capacity)

preservatives give no protection against non-bacterial pathogens such as viruses, protozoa and prions

Inhibitors of histone acetyltransferases KAT6A/B induce senescence and arrest tumor growth