b12 injection sq or im vitamin Store Intramuscular vs Subcutaneous Injections for vitamin B12 supplements Injecting B12 - Enhance Me

B complex injections can slightly sting during the injection, this is normal and the sensation should subside shortly after the injection is completed

New Insights on Muscle Strength: The Role of Inhibiting an Enzyme that Hinders NAD+ Synthesis University of Texas Medical Branch researchers show that treating with an inhibitor of an enzyme that breaks down an NAD+ precursor enhances muscle strength and endurance and shortens recovery time in aged mice

The takeaway across the whole timeline is simple

It's likely to be accompanied by other neurological deficits though, and it's worth remembering that muscle stiffness and pain can be caused by many other things