B12 injections are an effective and rapid treatment for your body to quickly and efficiently absorb the vitamin it needs (NIH, n.d.)
Rubbing can cause bruising and may spread the medication outside the intended injection zone
Importantly, supplementation can **increase** measurable NAD+ metabolism: in a 2018 randomized, placebo-controlled crossover trial published in Nature Communications by Martens and colleagues at the University of Colorado Boulder (24 healthy middle-aged and older adults), 1,000 mg/day of the NAD+ precursor nicotinamide riboside (500 mg, twice daily) elevated NAD+ in blood cells by roughly 60% versus placebo over 6 weeks, with no serious adverse events reported
Multi-Function Formula Skin whitening, hydration, anti-aging & detoxification in one
Am J Physiol Endocrinol Metab (2011) 301(2):E31725.10.1152/ajpendo.00077.2011 133 FengRQianCLiuQJinYLiuLLiSet alExpression of sweet taste receptor and gut hormone secretion in modelled type 2 diabetes