How to Give a B12 Injection: Step By Step Instructions B12 vitamin Store Needle and Syringe Information for injecting vitamin B12 and vitamin C. Find out what needle sizes are recommended. B12 Injections at Allura Skin, Laser & Wellness Clinic Dr. prescribed B12 injections. Pharmacy only gave me vials. Where do you get your needles and syringes? What size?? Where do I inject? : r B12_Deficiency B12 Injection Shots Order Online! Amazon.com: Ulove Prs 12 Pack 1ml Industrial Syringes with 25Ga 1 Inch Needle, Plastic Disposable Syringe and needle for Scientific Labs, Liquids Refilling and Measuring : Industrial & Scientific