Hydroxocobalamin, the form most commonly used in the UK, may cause: Injection site reactions (pain, redness, or swelling) Temporary reddish discolouration of urine Rarely, hypersensitivity reactions Very rarely, hypokalaemia in severely deficient patients when treatment is initiated (potassium levels should be monitored in severe deficiency) B12 injections are considered very safe, with no upper tolerable limit established, as excess B12 is excreted in urine
Its designed to support your bodys natural hormone pulses
[15] [16] Tests may include full blood count, serum B12 levels, anti-intrinsic factor antibodies (to diagnose pernicious anaemia), and sometimes methylmalonic acid or homocysteine levels when the diagnosis is uncertain
Neurochem Res 37(8):16011614
But studies have not shown a strong effect