If you experience severe pain, signs of infection (redness, warmth, swelling), or an allergic reaction (rash, itching, difficulty breathing), seek medical attention immediately
It also depends on how well the body absorbs it
B12 Injections: How Often
the clinical relevance of this finding in humans is unknown, and in UK and EU prescribing information this is noted as a precaution rather than a formal contraindication but individuals with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2 (MEN2) should discuss this with their doctor
Medically Reviewed on 6/10/2026 Harvard T
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