why do i have to have b12 injections How Long Last? B12 Shots for Weight Loss:

Furthermore, elevated levels of pro-inflammatory interferon (IFN-), tumor necrosis factor (TNF-), and granzyme B (produced by CD8 + T cells) increased the IFN- level in the adipose tissue of middle-aged mice [11]

Adverse reactions reported following methylcobalamin administration include headache, infection, nausea/vomiting, paresthesias, and rhinitis

Someone with a real B12 shortage may feel a bigger change from B12

Most multivitamins that contain B12 have 5 to 25 mcg per dose, while supplements that contain only B12 usually have higher doses in the 500 to 3,000 mcg range

You can acquire Vitamin B12 supplements over the counter as sprays or tablets