One ingredient widely recognised for its role in supporting skin whitening and clarity from within is L-glutathione
also identified as G6PDH)
Janelidze S, Hertze J, Ngga K, Nilsson K, Swedish BioFINDER Study Group, Nilsson C, Wennstrm M, van Westen D, Blennow K, Zetterberg H, Hansson O (2017) Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype
That's not a flaw in the supplement, it's just how antioxidant biology works your body finishes its internal repair job before it starts showing up in the mirror
The key to this entire process is precision
61:104-108 Masayuki Ikeda, Makoto Asai, Takahiro Moriya, Masami Sagara, Shojiro Inou, Shigenobu Shibata, Methylcobalamin amplifies melatonin-induced circadian phase shifts by facilitation of melatonin synthesis in the rat pineal gland, Brain Research, Volume 795, Issues 12, 8 June 1998, Pages 98-104, ISSN 0006-8993, Carmen Wheatley Cobalamin in inflammation III glutathionylcobalamin and methylcobalamin/adenosylcobalamin coenzymes: the sword in the stone