Sources: Institute of Medicine, Food and Nutrition Board, National Academies of Science, Dietary Reference Intakes (DRI): Recommended Dietary Allowances and Adequate Intakes , USA 2018, Mustafa Vakur Bor, Kristina M von Castel-Roberts, Gail PA Kauwell, Sally P Stabler, Robert H Allen, David R Maneval, Lynn B Bailey Ebba Nexo Daily intake of 4 to 7 g dietary vitamin B-12 is associated with steady concentrations of vitamin B-12related biomarkers in a healthy young population Am J Clin Nutr 2010 91: 3 571-577
Red Fox Peptides sources pharmaceutical-grade GHK-Cu with full COA documentation available
Nature (2021) 594:1005
What best describes your main concern
Vitamins are a very common cause of metallic taste in your mouth
You should work with medical professionals whatever option you pick