Yes, supplementing vitamin B12 is generally very safe and beneficial especially in cases with gastrointestinal disease coupled with weight loss
A randomized, double-blind, placebo-controlled trial in 191 older adults (75 years) with moderate vitamin B 12 deficiency (serum cobalamin concentrations of 107-210 pmol/L) without anemia provided participants with 1 mg/day of cyanocobalamin for one year (94)
doi:10.1038/nature13198 PubMed: 24717514 Pissios P
Different from full-length GH (experimental): Research suggests minimal effect on IGF-1 and limited activation of classical growth hormone receptor signaling compared with intact GH
He explained that the blend had been screened using two different immunoassay test strips and that both returned positive results
Therefore, before establishing expectations on B12 shots, you should talk to your doctor to see if you need to adopt a healthier lifestyle or take additional supplements in addition to B12 injections