Vegans, vegetarians, people over the age 50, anyone with stomach/bowel issues like chronic gastritis, leaky gut, IBS or celiac, and anyone who regularly takes medications such as Metformin, PPIs (used for GERD), H2 Receptor Antagonists (used for peptic ulcers), or anything that interferes with stomach acid production are actually at risk for vitamin B12 deficiency, and should supplement B12 regularly
Injection depth matters
That distinction is not currently being made on most of the websites selling the compound
Where you aim the stream matters
Vitamin B12 plays essential roles in red blood cell formation, neurological function, and DNA synthesis
Hydroxocobalamin can be naturally produced by gut bacteria when digesting food but is also another man-made form of B12 that can be easily absorbed and used by the body