how long for b12 injections to work Shots at Home: How, Where & Often Inject Yourself b12 injection working time If

Seek urgent same-day assessment or call 999 for emergency care if experiencing: Severe chest pain Severe shortness of breath Fainting or collapse Acute or rapidly worsening neurological deficits (such as new limb weakness, sudden gait disturbance, or bladder/bowel dysfunction) Persistent or worsening anaemia symptoms despite treatmentincluding breathlessness, chest discomfort, palpitations, or extreme fatigueshould trigger medical review

Lifestyle factors: Certain lifestyle factors, such as diet and exercise, can also influence the duration of B12 injection benefits

This may happen because of certain stomach or bowel conditions, previous surgery, pernicious anaemia or other medical reasons

Vitamin B12 is best injected intramuscularly into the deltoid (upper arm), thigh, or gluteal muscle (buttocks)