Expert opinion Hunt et al 23 Data from randomized controlled trials and observational studies for parenteral treatment are lacking
Hydroxocobalamin 1mg is the standard UK formulation, typically administered every two to three months for maintenance therapy Self-administration requires GP prescription, competency training from practice nurses, and demonstration of proper injection technique Common injection sites include the thigh (vastus lateralis) for both intramuscular and subcutaneous administration with site rotation essential Serious side effects are rare but anaphylaxis requires immediate 999 call
Many people report feeling less exhausted within about 2 or 3 days of getting their first B12 injection
Injections are particularly beneficial for those who are pregnant, who may follow a vegetarian or vegan diet, as it can more accurately ensure that both mum and baby are getting the right volume that they need
Results depend heavily on baseline body composition, dietary adherence, exercise programming, sleep quality, stress management, genetic factors, and protocol compliance