Glutathione depletes, and we can no longer protect ourselves and get rid of toxins causing the toxins to stick to the glutathione molecule
In: Elsner P., Maibach H., editors
5,6, 7 Additionally, there is suppression of other melanocyte metabolic processes decreasing melanin formation via selective damage to melanosomes and melanocytes through production of reactive oxygen radicals
Since then, several clinical studies have shown its safe and effective use - but the pharmacuetical companies have decided not to (yet) pursue FDA-Approval (likely because each new FDA-Approval costs several million dollars to go through the process, and because there are a good deal of drugs used off-label in the way tranexamic acid is for melasma, especially when the drug has a long history of safety and efficacy, as is in this case)
Related to GHK-Cu (the copper-bound form) studied in the Pickart & Margolina review