Blood clots are gel-like clumps of blood
Work under aseptic conditions with sterile syringes and alcohol-swabbed stoppers
Proper Disposal Dispose of all materials in accordance with institutional biosafety, chemical waste, and hazardous material protocols
Defined onset window Peak plasma at ~1 hour with a 2.7-hour half-life gives a predictable research window without prolonged exposure
National Institutes of Health, Office of Dietary Supplements
You should contact your GP if: You have been found to have elevated B12 levels on blood tests, particularly if levels exceed 1000 ng/L (approximately 740 pmol/L, though laboratory reference ranges vary) and you are not taking high-dose supplements You develop new symptoms after starting B12 supplementation, including persistent skin rashes, significant gastrointestinal disturbance, or unexplained symptoms You have underlying liver disease, kidney problems, or blood disorders and are considering B12 supplementation You are taking B12 supplements without medical supervision and have not had your levels checked, particularly if taking doses exceeding 2000 micrograms daily You experience symptoms that might indicate underlying disease, such as unexplained weight loss, persistent fatigue, jaundice, or abdominal swelling Call 999 or go to A&E if you develop severe allergic reactions following B12 injections, including difficulty breathing, facial swelling, or widespread rash, as these may indicate anaphylaxis, though this is extremely rare
