Gold Member Badge


  • You're all caught up!

How is a B12 Injection Given?

author image Sarka-Jonae Miller
Sarka-Jonae Miller has been a freelance writer and editor since 2003. She was a personal trainer for four years with certifications from AFAA and NASM. Miller also worked at 24 Hour Fitness, LA Fitness and as a mobile trainer. Her career in the fitness industry begin in 2000 as a martial arts, yoga and group exercise instructor. She graduated cum laude from Syracuse University.
How is a B12 Injection Given?
How is a B12 Injection Given?


Vitamin B12 injections contain a man-made version of the vitamin called cyanocobalamin. There are also some versions made with hydroxocobalamin. Injections of B12 give you an average of 500 times the daily recommended amount of B12. Vitamin B12 is important for cell division, blood formation and synthesizing protein and tissue in the body. It is essential for healthy cardiovascular and nervous systems. Injections are administered to people deficient in this important vitamin or who have a disease called pernicious anemia. Pernicious anemia sufferers have trouble with the absorption of vitamin B12. B12 injections are said to help people sleep, increase energy and improve focus.


Check with your doctor before getting a B12 injection, as it is dangerous for people with Leber's disease or an allergy to cobalt or cobalamin. The size of your dose will also be different if you are pregnant or a vegetarian. You will also want to consult your physician if you have an infection, kidney disease, liver disease, an iron deficiency, a folic acid deficiency or are taking medication that affects bone marrow. Your physician may need to run some tests or suggest a different dosage.

How to Give Yourself an Injection

Talk to your doctor about an appropriate dosage and familiarize yourself with the instructions. Ask your physician if you have any questions or are unclear about any part of the procedure. Wash your hands. Pick a spot for the injection. You should choose an area with muscle. Pinch your skin. Insert the needle at an angle. Once the needle is in you can release the skin and push down to inject the B12. Take the needle out and disinfect the area.

Side Effects

People in general do not have problems accepting high dosages of vitamin B12. Rarely do side effects occur, but serious side effects are possible. Some of the most significant ones are swelling, chest pain, trouble breathing, quick weight gain, or redness or pain in your arms or legs. Other side effects include diarrhea, headaches, nausea, fever, itchiness and joint pain. Call your doctor if you experience any of these symptoms.

LiveStrong Calorie Tracker
Lose Weight. Feel Great! Change your life with MyPlate by LIVESTRONG.COM
  • Gain 2 pounds per week
  • Gain 1.5 pounds per week
  • Gain 1 pound per week
  • Gain 0.5 pound per week
  • Maintain my current weight
  • Lose 0.5 pound per week
  • Lose 1 pound per week
  • Lose 1.5 pounds per week
  • Lose 2 pounds per week
  • Female
  • Male
ft. in.


Demand Media