The mechanism involves upregulation of matrix metalloproteinases (MMPs) and their inhibitors, which remodel collagen in a more organized way than unassisted healing
DOI 10.1111/dom.14725 - about two-thirds regain within a year
[DOI] [PubMed] [Google Scholar] 37.Beck-da-Silva L, Higginson L, Fraser M, Williams K, Haddad H
Deficiency may result from several things including: Pernicious anaemia where your body cannot absorb B12 efficiently from food Diets low in B12-rich foods Certain medications, including some contraceptive pills, that interfere with absorption Low B12 levels can manifest in several ways, and many of these symptoms directly affect hair health
toxicity studies show low systemic absorption and no observed adverse effects at standard cosmetic concentrations (0.53%)
And it's not just about the feeling of energy