how quickly does a b12 injection take to work Fast Vitamin Shot Work? Feeling worse after B12 Injection:

These may include: ( 4 ) Fatigue or lack of energy Brain fog or trouble concentrating Irritability or mood swings Pale skin or shortness of breath Tingling in the hands and feet Difficulty walking or staggering Anemia Swollen or inflamed tongue A B12 deficiency in men may also contribute to low testosterone, weight gain, and poor exercise recoverymaking it a hidden factor in many mens health concerns

Interruption of Pain Signal Pathways Pain signals from the affected area cannot reach the central nervous system during its action

This can happen with deeper injections, such intramuscular or intravenous injections

it's a piece of a much larger, intricate puzzle

Nasser Nasseri