B12 injections take the express lane
Severe B12 deficiency is widely reported and leads to pernicious anemia since your body needs B12 to make red blood cells, and a deficiency limits its capabilities to build them
Look out for fatigue , weakness , and neurological changes like numbness
Potential Side Effects and When to Seek Medical Advice B12 injections are generally well-tolerated, with serious adverse effects being rare
Post-treatment serum B12 measurements can be misleadingly high and may not accurately reflect tissue levels, so your GP will focus on symptom improvement and clinical assessment
Route, food, metabolism, and product quality could all change how long the compound remains in the body