You will see it stated confidently in a lot of places that the body adapts after 4 to 6 weeks, tolerance builds, and the effect fades, so you have to cycle. It sounds authoritative
For vitamin B12 to be absorbed from the gut, it must bind to a protein called intrinsic factor, which limits how much B12 the gut can take in at one time
When youre losing fat actively, the bodys demand for the cofactors that drive metabolism (including B12, B6, folate) goes up while supply goes down
5.3 Masking of Folate Deficiency with Vitamin B12 Use Doses of vitamin B12 exceeding 10 mcg daily may produce hematologic response in patients with folate deficient megaloblastic anemia and may therefore mask a previously unrecognized folate deficiency
COAs are available on request
Benzyl Alcohol Warning: Some forms of vitamin B12 injections contain benzyl alcohol