Vitamin B12 Dosages: Your GoodRx Guide GoodRx 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 Hi everyone, I am now taking bookings for B12 injections. A course is recommened to help the vitamin get into the system. One a week x4 weeks One a fortnight (over 4 How Long Do Vitamin Injections Last? Here's the Fact B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Cyanocobalamin Injection USP 1000 mcg mL