how fast does b12 injection work Long Do Injections Take to Work? Feeling Tired? Vitamin B12 Shots

Most are animal sources (milk, egg yolks, yogurt, salmon, tuna, beef) which is why vegetarians and vegans have a higher risk of being deficient (3)

Many patients with tingling or numbness begin to notice a reduction over months two and three, with further recovery beyond six months

Vitamin B12 injections begin working at a cellular level almost immediately after administration, though the timeframe for noticeable symptom improvement varies considerably between individuals

You should also contact your GP if: You are unable to attend scheduled maintenance injections, as missing doses can lead to symptom recurrence You develop new symptoms that might indicate other deficiencies or health problems You are planning pregnancy, as B12 requirements may change You experience persistent side effects such as headaches, dizziness, or gastrointestinal symptoms If you experience any side effects, talk to your doctor, pharmacist or nurse