Figure. Subcutaneous injection into the deltoid area The Australian Immunisation Handbook Semaglutide B12 Injection HydrationStaytion Best Vitamin B12 Injection Sites MedHealth 360 B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Vitamin B12 Injections Energy Boost The Center Medical Deltoid Muscle Injection , The deltoid muscle is a common site for intramuscular (IM) injections, especially vaccines! , What gauge needle do you use for an IM injection? Answer in the comments!,