are b12 injections subcutaneous or intramuscular at Home - Safety Guide for Self-Administration Vitamin B12 Injection Methods: Choosing

"Advances in the understanding of cobalamin assimilation and metabolism"

Mechanism of Action 5-Amino-1MQs mechanism centers on selective inhibition of nicotinamide N-methyltransferase, with downstream metabolic effects mediated through changes in cellular methyl-donor availability, NAD + precursor flux, and adipocyte energy expenditure

The other seven have no FDA approval and exist only as unregulated research chemicals not meant for human use

Indications and Usage: Methylcobalamin, Folic Acid, Niacinamide Injection is indicated for the treatment of vitamin deficiencies, including vitamin B12 deficiency, folate deficiency, and niacin deficiency