vitamin b12 injection administration Treating Severe Deficiency | B12 IM How to Inject Vitamin B12

Its worth noting that adverse effects are not common with high supplemental vitamin B12 intake, however, there is also no strong evidence to show that it has benefits in people who are not already deficient (largely due to the fact that your body only stores as much B12 as it needs and any excess will be excreted through your urine)

Efficacy of Different Routes of Vitamin B12 Supplementation for the Treatment of Patients with Vitamin B12 Deficiency: A Systematic Review and Network Meta-Analysis. Irish Journal of Medical Science, 17 Jan

The time when you will notice significant changes in response to B12 supplementation is when you ask how long B12 takes to work

Sometimes, your body is just missing what it needs to function properly