sublingual b12 vs injection Table 2 from vitamin compared to intramuscular in patients with type 2 diabetes treated with metformin: a randomised trial Vitamin B12 Injections - Vie

Summary: There is no best time to take vitamin B12 specifically for weight loss, as B12 supplementation does not directly cause weight loss in individuals with adequate B12 levels

The injection provider can administer the B12 shot deep into the muscle (intramuscularly) or into the tissue layer between the skin and the muscle (subcutaneously)

McCormack, M

It's almost certain someone in your circle has an undiagnosed pernicious anemia

Vitamin B12 (methylcobalamin) , which can naturally tint the solution a pinkish hue

Any condition affecting the gastrointestinal tract, such as autoimmune gastritis (which can lead to pernicious anaemia), celiac disease, Crohns disease, or surgical procedures like gastric bypass surgery, gastrectomy or terminal ileal resection, can impair the absorption of B12, and increases the chance of developing vitamin B12 deficiency