Even when a small fraction does reach the viable epidermis, the molecule has a short functional half-life unless it is stabilized in the formulation (encapsulation, copper chelation, or both) 1
Typical oral regimen: 250500 mcg 12 times daily, depending on severity of symptoms or goals
Poo MM, Pignatelli M, Ryan TJ, Tonegawa S, Bonhoeffer T, Martin KC, Rudenko A, Tsai LH, Tsien RW, Fishell G, Mullins C, Gonalves JT, Shtrahman M, Johnston ST, Gage FH, Dan Y, Long J, Buzski G, Stevens C (2016) What is memory
suggested a difference in the individual MTHFR gene variation ( In contrast to the aforementioned study ( Importantly, we did not preselect patients based on a positive response to previous vitamin B12 injections, leading to more generalizable results in our study
The distinguishing feature is usually that B12-related mood symptoms don't appear in isolation
[4] Eli Lilly