PMID 31279840
Symptoms of vitamin C deficiency, such as poor wound healing and lethargy, likely result from the impairment of these vitamin C-dependent enzymatic reactions leading to the insufficient synthesis of collagen, carnitine, and catecholamines (see Deficiency)
Does it have completed human trials behind it
Because B12 shots are administered intramuscularly, they bypass the digestive system, allowing the body to absorb a much larger amount of B12 that would otherwise be lost during digestion

Increased absolute concentrations of intracellular NAD + links with activation of NAD + -dependent histone deacetylases (e.g., sirtuins) that also mediate epigenetic regulation of gene expression[40] and adipocyte physiology.[45] Similarly, increased intracellular concentrations of SAM, a universal substrate for SAM-dependent histone methyltransferases, could have profound influence on cellular epigenetic modifications, including transcriptional regulation and the expression of genes that regulate adipogenesis and/or thermogenesis promoting browning of adipocytes (e.g., PPAR, PRDM16, UCP1, Wnt).[4648] NNMT protein expression is relatively lower in the murine brown adipose tissue (BAT) compared to the WAT [37] and nnmt (a WAT-selective gene [49, 50]) gene expression has been reported to be lower in the BAT of HFD fed mice compared to normal chow-fed mice.[49] Furthermore, NNMT activity is significantly higher in the white fat compared to brown adipose tissue and the other organs (e.g., liver, lungs) in DIO mice.[16] Hence, treatment with an NNMT inhibitor in DIO mice may less likely impact BAT or other tissue NNMT activity, but could be speculated to modulate thermogenic/adipogenic genes in the WAT

Many clients report feeling more energized and less fatigued after treatment, which can enhance your ability to stick to your fitness and health goals