Common adverse effects include: Injection site reactions pain, redness, swelling, or bruising at the intramuscular injection site Gastrointestinal disturbances nausea, diarrhoea, or abdominal discomfort Headache and dizziness particularly following initial doses Skin reactions including rash, pruritus, or acne-like eruptions Flushing temporary redness of the skin Chromaturia red-coloured urine (harmless but can cause concern if unexpected) Less common but more serious reactions include: Hypersensitivity reactions ranging from mild urticaria to anaphylaxis (rare but potentially life-threatening) Hypokalaemia particularly during initial treatment when rapid cell production occurs [5] [16] Temporary changes in blood counts during correction of deficiency Interference with laboratory tests primarily with high-dose IV hydroxocobalamin used for cyanide poisoning, not typically with standard 1mg IM replacement doses Cautions and contraindications: Hypersensitivity to cobalt or vitamin B12 Cyanocobalamin should be avoided in Leber's hereditary optic neuropathy [2] [17] Chloramphenicol may reduce the haematological response to B12 therapy Patients receiving B12 injections outside clinical necessity face unnecessary risks without proven benefit

Chandran V
A recent systematic review (Vasireddi et al., Am J Sports Med 2025) confirms the potential in sports medicine
NS optional) Vita Blend B1 300mg, B2 6mg, B3 300mg, B5 6mg, B6 6mg Amino Blend Proline 100mg, Arginine 200mg, Lysine 100mg, Citrulline 100mg Ascorbic Acid (Vitamin C) 2000mg Magnesium Chloride 600mg Zinc Sulfate 10mg Alpha Lipoic Acid (ALA) 100mg (pre-infusion push) NAD+ 300mg (secondary NS or LR 1000ml bag
Boosted weight-loss efforts: Enhances progress when used alongside your current weight-loss plan