It contains a cyano (cyanide) group in its structure, which makes it more stable than other forms of vitamin B12 as the cyanide stabilizes the molecule from deterioration
Some people do well with an oral or sublingual supplement
Subcutaneous amounts are community research practices, not an approved clinical protocol
Drug Testing and Analysis, 7(1), 3138
More specifically, to develop the model we used experimental data from two sources: i) isolated adipocytes treated in vitro with the -adrenergic agonist isoproterenol to stimulate lipolysis, and additionally with insulin to inhibit the isoproterenol-stimulated lipolysis, from [3], and ii) microdialysis measurements of lipolysis in vivo , stimulated with adrenaline/isoproterenol and inhibited by insulin and phentolamine, from [4]