Are you feeling run down? Low Energy? A quick Vitamin B12 injection can help support energy, metabolism, and overall wellness. It delivers the vitamin directly into the muscle, allowing your body to B12 Injection Frequency: How Often Should You Get a B12 Shot? Liv Hospital If you have a low vitamin B12 level, injections can go a long way toward improving your health and well being. But if your B12 level is normal, don't fall for claims that How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust