What Happens If You Inject B12 Wrong: 6 Red Flags 1 Box Vitamin B12 Methylcobalamin injectable shots.. Includes Syringes and F VIAVQ VITAMIN Lets do my first B12 injection together This is something Ive been nervous about for a long time, but today I finally did itand it honestly wasnt bad at all. I used the Union Medico needle guide Vitamin B 12 Cyanocobalamin Injection 1000MCG mL 30 mL MDV Med Plus Physician Supplies