Laboratory and/or medical tests (e.g., serum potassium levels, complete blood count, hematocrit, vitamin B-12 levels) should be performed to monitor your progress or check for side effects
Nature Reviews Molecular Cell Biology, 16(7), 397408
Summary: Vitamin B12 toxicity from supplementation is extremely rare, but persistently elevated serum levels may indicate underlying liver disease, kidney dysfunction, or haematological disorders requiring medical investigation
Vegetarians and vegans are at higher risk of B12 deficiency because B12 comes mostly from animal foods, so the B12 in a B12/lipotropic injection is more likely to correct a real shortfall and lift your energy
Users do not report the hand numbness, tingling, or grip weakness associated with carpal tunnel