Treating Severe Vitamin B12 Deficiency B12 IM Injection VanishPoint 29 Gauge x 5 16 inch Retractable Insulin Syringe with Needle 1 mL, Regular Wall, 100 Box Know Your Needles A Quick Nursing Guide! Today, let's understand the different types of needles and their clinical purposes Green Needle (21G) For IM injections like Does size matter? Historically, a bigger needle gauge was considered better to prevent damage to red blood cells. However, our recent guidelines recommend using smaller gauge needles (2325 G) for all