According to British Society for Haematology (BSH) guidelines and NICE Clinical Knowledge Summaries (CKS), the primary beneficiaries include: Key patient groups who may require B12 injections include: Pernicious anaemia patients requiring lifelong hydroxocobalamin 1mg intramuscularly every 23 months following initial loading doses Patients with gastrointestinal disorders including those who have undergone gastrectomy or ileal resection, and patients with conditions affecting B12 absorption such as Crohn's disease or coeliac disease Strict vegans and vegetarians though oral supplementation is usually sufficient unless malabsorption is present Elderly patients who may have reduced gastric acid production affecting B12 absorption Patients taking certain medications including metformin (MHRA advises monitoring B12 levels in long-term users, particularly those with risk factors or symptoms), proton pump inhibitors, and H2-receptor antagonists long-term [6] Individuals with neurological symptoms such as paraesthesia, ataxia, or cognitive impairment related to B12 deficiency Pregnant women with confirmed deficiency (hydroxocobalamin for malabsorption

If it were a breakthrough fat-loss drug, it would likely still be in aggressive pharmaceutical development
B12 shots can help restore healthy B12 levels more quickly than oral supplements because they bypass the digestive tract and absorption process
Neuropathic pain: Definition, assessment and epidemiology
Form : Oral capsules (most common for 10mg)
Some of these include nausea and pain at injection site