Petraglia F, Vannuccini S, Santulli P, Marcellin L, Chapron C
Common, mild side effects: Pain, redness, or itching at the injection site Mild nausea or diarrhea Headache Temporary dizziness Rare but more serious reactions: Allergic reactions (rash, swelling, breathing difficulty) Heart palpitations Low potassium levels during rapid correction of severe deficiency Very rare cases of anaphylaxis requiring emergency care Seek medical attention immediately if you experience symptoms of a serious allergic reaction
You or your child may need to remain in your doctors office for several minutes following the immunization(s) to ensure there are no adverse complications, such as dizziness or allergic reactions
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
Country of origin :-INDIA