how often should you have a b12 injection Injections? The Timing of B12 Injections:

, 60

PMID 19832808

Visible signs of aging : Skin relies on NAD+ for collagen production, repair, and protection against oxidative stress

It's also important to remember that if you have Leber's disease, a specific type of B12 called cyanocobalamin could be harmful to your optic nerve

D51.1 - Vitamin B12 deficiency anemia due to selective vitamin B12 malabsorption with intrinsic factor deficiency: Applied when macrocytic anemia results from selective vitamin B12 malabsorption with intrinsic factor deficiency, affecting vitamin B12 absorption

All of them will work, but some will just be more comfortable to use