how long does the vitamin b12 injection take to work Injections and Weight Loss: it Work? Are B12 Shots Safe? Royal

Vitamin B12 shots work right away and your body will begin to manufacture new red blood cells as early as 48 hours so you will feel the effect in two or three days

Symptoms can develop quickly and include: feeling faint or lightheaded difficulty breathing or wheezing rapid heartbeat confusion anxiety clammy skin collapsing or losing consciousness hives swelling stomach pain, nausea, or vomiting If you or someone nearby develops these symptoms, you should: Check to see whether they have an epinephrine pen

Generally, the frequency differs from person to person and is decided by the doctor

Experiencing arm pain after a shot is common and usually not a cause for concern