When a compound has no completed human trial, there is by definition no safety data in any subgroup no pregnancy data, no hepatic-impairment data, no interaction data with common metabolic or endocrine medications
Not in the glove box
How to Administer Vitamin B12 Injections Vitamin B12 injections are usually administered intramuscularly, meaning the injection is given directly into a muscle
Wheatcroft SB, Kearney MT, Shah AM, Ezzat VA, Miell JR, Modo M, Williams SCR, Cawthorn WP, Medina-Gomez G, Vidal-Puig A, Sethi JK, Crossey PA
[2] NNMT transfers a methyl group from S-adenosyl-L-methionine (SAM) to nicotinamide
PMID 21436999