If you follow a vegan diet, lack B12-rich food, or suffer from health conditions like B12 deficiency, which happens when a person cannot absorb it properly, then you may experience b12 deficiency
Most people having B12 injections (intramuscular) will see an improvement in the first 24 hours, but the hematological response, including the quick production of new red blood cells, may take several days to months for a full response
Bezabeh T, Mowat MR, Jarolim L, Greenberg AH, Smith IC
Some people use vitamin C in the morning and copper peptides at night to reduce irritation, since layering many actives can sting on reactive skin
Their results suggest that activation of CMA is involved in the execution of ferroptosis through GPX4 degradation in cell lines from different tissue origins [45]
It has not yet received FDA approval, so it is classified as a research compound