If youre vegan or mostly plant-based, oral or sublingual B12 is usually enough long term shots are typically for documented deficiency or absorption issues (NIH ODS)
You can use the deltoid or gluteal muscles
Interesting fact: vitamin B12 was isolated, crystallized, and characterized in the laboratory of Dorothy Hodgkin, contributing to her Nobel Prize in 1964. 1 Vitamin B12, also called cobalamin, plays a key role in the formation of DNA and red blood cells, and in maintaining healthy brain and nerve cells
Are There Serious Risks of B12 Injections
What is the recommended dosage per injection
A 1996 study out of Germany found that periods of intensive training or racing were associated with a three- to six-fold increase in GI blood loss