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 practical rule: if your maintenance dose will be 8 mg or 12 mg, start with 20 mg/mL from the beginning
With the stuff at Labs, the benefit is well worth the risk, because the risk isnt very high
The 100mg vial answers with a lower cost per milligram and with batch continuity across a larger body of work, since one batch and one certificate of analysis cover twice as much
One of the most remarkable characteristics of GHK-Cu peptides is their ability to visibly smooth fine lines and wrinkles