how soon does b12 injection start working Long It Take for Injections to Work? Feeling worse after B12 Injection:

Food and Drug Administration (1)

No , B12 usually has the opposite effect

Vitamin injections may support other treatments by: Supporting recovery after surgery Reinforcing overall wellness goals Complementing holistic health plans Helping address specific nutrient-related concerns Offering ongoing maintenance support This kind of pairing can be especially helpful when clients want their wellness plan to feel more proactive and personalized

However if your B12 is already borderline that could be enough reason for you to avoid it

The MHRA has previously taken enforcement action against suppliers of unlicensed injectable peptides and has issued public warnings about the dangers of purchasing such products online