Additionally, the enteric nervous system (ENS), often referred to as the second brain, can also influence brain function via local signaling mechanisms
supplier is the reliable route
Rubin P, Jewell ML, Richter D, Uebel CO
UK B12 treatment for B12 deficiency without neuro symptoms is 6 loading jabs over 2 weeks followed by a jab every 3 months for B12 deficiency with neuro symptoms present, it is a B12 loading jab every other day for as long as symptoms continue to get better (could mean loading jabs for weeks even months) then a jab every 2 months UK b12 documents BMJ B12 article bmj.com/content/349/bmj.g5226 BSH Cobalamin and Folate Guidelines b-s-h.org.uk/guidelines/gui
Genetic differences in detoxification pathways explain why some people are more sensitive
The article ties that difference to fewer administrative barriers on the self-pay path, including no prior authorization step standing between the intake and the prescription