glutathione nasal spray benefits Intranasal Longevity & Vitality Programs -

Another study emphasized the potential adverse effects of copper exposure on myocardial contractility at recommended daily doses, tolerable maximum intake doses, and twice the tolerable maximum intake level, but the validity of these doses requires verification through extensive experimentation (122)

You should also skip it if you are sensitive to or allergic to benzyl alcohol (a preservative found in some GSH products)

Intravenous (IV) Vitamin C With Chemotherapy for Cisplatin Ineligible Bladder Cancer Patients 138

You can check your vitamin B12 levels using a routine blood test called the vitamin B12 level test