Vitamin B12 is important for cell reproduction, blood formation, brain development, and bone growth. Individuals suffering from the symptoms of low vitamin B12 (or pernicious anemia), such as depression, exhaustion, anemia, and poor memory, may ask their doctor about vitamin B12 injections.  The physician will draw blood to measure the total blood levels of vitamin B12 in your body, and if they are low then B12 injections may be an option. Vitamin B12 injections contain a man-made form of vitamin B12 called cyanocobalamin. You should also speak to your doctor about allergies or other conditions which may have an adverse reaction to vitamin B12.  Though you can self-administer vitamin B12 injections, the safest way is to have someone give you the injection after being trained by a healthcare professional. 
I had three injections all of which worked for a few days to two weeks then stopped. The excruciating pain returned and only Vicoden 5 mg 3-4 times a day controlled the pain. Vicoden at that dose is the lowest dose prescribed. it worked perfectly for several years and doctors refused to prescribed opioids for fear of losing their license. My sister recently died of throat cancer and she complained constantly of pain. She died with unrelieved pain. As a cancer patient she was prescribed Morphine 2 mg. every 6 hours. That is beyond ridiculous but keeps our doctor’s license safe. Our doctors are violating their Hippocratic oath – Do No Harm. They had added a caveat “except when the government is breathing down your neck. Then the patient be damned. I am glad this helped you Randy. I don’t know your clinical status but I am sure it differs from mine. Do you have severe and crippling arthritis?