Vitamin B12 shots deliver a concentrated dose of this essential nutrient directly into the body. Administered into a muscle, these injections bypass the digestive system, ensuring optimal absorption and allowing the vitamin to enter the bloodstream efficiently.
Preparing for the Injection
Gather all necessary supplies: the prescribed vitamin B12 solution, a clean syringe and needle (often two different needles are recommended: one for drawing up and one for injecting), alcohol wipes, cotton balls or sterile gauze, and a sharps container for safe disposal. Ensure a clean, sterilized surface.
Wash hands thoroughly with soap and water for at least 20 seconds, cleaning between fingers and both sides, to prevent infection. Dry hands completely; sterile gloves offer additional protection.
Prepare the B12 vial or ampoule. If using a vial, wipe the rubber stopper with an alcohol wipe and allow it to air dry for several seconds. For an ampoule, gently tap the top to ensure all the solution is at the bottom, then use an alcohol wipe and a gauze pad to snap the top off, away from your body.
Draw the medication into the syringe. Attach a drawing needle to the syringe. For a vial, inject an amount of air equal to the dose you intend to withdraw to prevent a vacuum, then invert the vial and slowly pull back the plunger to draw the prescribed amount of B12 solution. Remove any large air bubbles by gently flicking the syringe and pushing the plunger until a small drop appears at the needle tip. Replace the drawing needle with the injecting needle, which is typically a 22-25 gauge and 1 to 1.5 inches long for intramuscular injections, or a 25-27 gauge and 3/8 to 5/8 inch for subcutaneous injections.
Administering the Injection
Choose the correct injection site for effective B12 administration. Intramuscular (IM) injections deliver medication deep into muscle tissue for rapid absorption. Common IM sites include the deltoid muscle in the upper arm, the vastus lateralis muscle in the outer thigh, and the ventrogluteal or dorsogluteal areas of the buttocks. The thigh is often recommended for self-administration due to ease of access.
Clean the chosen site thoroughly with an alcohol wipe. Wipe in a circular motion, starting from the center and moving outwards about two inches, then allow the alcohol to dry completely to prevent stinging. For an intramuscular injection, spread the skin taut at the injection site or, in some cases, bunch up the muscle, depending on the site and technique.
Hold the syringe firmly like a dart in your dominant hand. Insert the needle swiftly and smoothly at a 90-degree angle to the skin, ensuring it reaches deep into the muscle. While some older guidelines suggested aspirating (pulling back on the plunger) to check for blood, current guidance for B12 injections often deems this unnecessary. Slowly and steadily push the plunger to inject the medication over approximately 5-10 seconds per milliliter, allowing muscle fibers to stretch and retain the medication and minimizing leakage. After the medication is fully injected, swiftly withdraw the needle at the same angle it was inserted.
After the Injection
Immediately after withdrawing the needle, apply gentle pressure to the injection site with a clean cotton ball or sterile gauze. Avoid rubbing or vigorously massaging the area, as this can increase irritation or bruising. A small drop of blood or medication may appear, which is normal, and a small adhesive bandage can be applied if needed.
Proper disposal of the used needle and syringe is crucial. Never recap a used needle, as this increases the risk of needlestick injury. Immediately place the entire used syringe and needle into a puncture-proof sharps container. If a commercial sharps container is not available, a heavy-duty plastic bottle with a screw-on lid can serve as a temporary alternative.
Monitor the injection site for reactions. Mild tenderness, redness, slight swelling, or bruising is common, typically resolving within 48 hours to two weeks. Mild dizziness, headaches, or temporary itching are also possible side effects. Keep the injection site clean and avoid unnecessary touching to prevent infection, and staying well-hydrated can aid in absorption. Contact your healthcare provider if you experience severe pain, persistent swelling, signs of infection (hot, shiny skin or pus), or any signs of a severe allergic reaction (facial swelling or breathing difficulties).