Gastrointestinal Disorders: People with gastrointestinal conditions, such as Crohn's disease, celiac disease, or atrophic gastritis, which might hinder the absorption of vitamin B12 from the diet, may be administered it
If you're on a 1ml weekly protocol and seeing no measurable change after six weeks, the problem is almost never 'too low a dose.' It's either formulation quality (underdosed methionine or choline), dietary interference (you're in maintenance calories, not deficit), or liver saturation (you're already consuming high dietary methionine and adding more doesn't shift the pathway further)
The necessity of adequately warning of the health and safety hazards associated with any products
Because the human body cannot synthesize Vitamin B12 on its own, it must be obtained entirely through diet or targeted supplementation
Some patients prefer an appointment-based approach because it feels easier to manage