Always good to have a reason I have also had this happen when my folate was low , it may be worth you getting it checked I had self inject my B12 every 4 weeks for the last 20+ (cannot really remember how long accurately), and 2 months ago got a similar 'electric shock tingling' all over my body - head, face, arms, hands, legs, feet etc within a couple of minutes of injecting, which lasted about 3 seconds or so
The economics of proper storage Proper storage is not just about maintaining potency
NAD-associated pathways and mitochondrial activity
Most people feel fine within a few days
Systemic Anti-Inflammatory Effects Because CKD is a state of chronic inflammation, BPC-157s ability to down-regulate inflammatory cytokines may help slow progression
Add methylmalonic acid if B12 levels are borderline