Stacking with other peptides targeting different mechanisms (such as GH secretagogues that work through the GHRH axis rather than direct fat-cell signalling) is theoretically additive
You can get vitamin B12 in the form of hydroxocobalamin, Methylcobalamin, and cyanocobalamin
In addition, the analgesic effect of melatonin is mediated through activation of supraspinal sites, inhibition of spinal nociception, and modulation of various neurobiological systems, including GABAergic, opioid, and glutamatergic systems [65]
Injection-site reactions are among the most commonly reported side effects: patients may experience pain, stinging, or mild burning at the IM injection site
Also, if you have chronic conditions like diabetes or neurological disorders, B12 shots might be part of your treatment