for what health issue are b12 injections used Vitamin Supplements and in Orlando FL Vitamin B12 shots: Uses, benefits,
Description
Skin should be smooth, and if you are injecting intramuscularly
PMCID: PMC4967041
Administration The injection is placed intramuscularly usually in the upper arm using sterile, single-use equipment

If I use an out of date one it makes no difference to me, so I know mine are still effective for me

however, anytime you receive an injection theres a slight risk of allergic reaction
WHAT RESEARCHERS LOOK AT Mechanism: selective small-molecule inhibition of NNMT