B12 Injections: Who Should Get Them and How Long Do They Last? Feeling run down from stressful work periods or just exhausted this winter? A Vitamin B12 injection could be the boost your body's been craving. In just 10 minutes, you can experience an Always Tired? B12 Injections Could Help Vitamin B12 is essential for energy production, nervous system function, and red blood cell formation. However, oral B12 supplementation doesn't work well for everyoneabsorption can be limited by digestive issues, certain medications, How Quickly Do Vitamin B12 Injections Work? Education Wow guys, you've been gate keeping!! Got my first B12 injection last week and it's like I am awake for the first time since having kids 20 years ago It's