do b12 injections help with fatigue does injection make you sleepy Feeling tired, foggy, or run-down? It could be a Vitamin B-12 Injection - Mobile

Many are compounded (custom-prepared)

For most patients, a weekly B12 shot for the first four weeks rebuilds depleted B12 levels, followed by maintenance shots every two to four weeks

Other metabolic implications of vitamin B 12 deficiency include the accumulation of homocysteine and methylmalonic acid, which might contribute to the neuropathologic features of dementia (63)

I had similar issues, though not as drastic as yours

Methylcobalamin injection is typically prescribed for individuals who have a deficiency of vitamin B12, particularly when the deficiency is severe or when there is a need for rapid replenishment of B12 levels