welche nebenwirkungen hat l-thyroxin — can a DNA test help?

L-Thyroxine (levothyroxine) is used to treat hypothyroidism. Most side effects stem from incorrect dosing: overdosing can cause palpitations, tremor, insomnia, anxiety, diarrhea, and sweating (hyperthyroid symptoms); underdosing may leave fatigue, weight gain, constipation, and cold intolerance. Allergic reactions are rare. Can a DNA test help? Some studies link variants in DIO2 (deiodinase 2) or THRB (thyroid hormone receptor) to altered hormone conversion or sensitivity, but the evidence is weak and not clinically actionable. Consumer DNA tests may claim to predict optimal dose or side effect risk, but effect sizes are small and replication is inconsistent. Current guidelines rely on TSH monitoring and clinical titration. A DNA test is not recommended for managing L-Thyroxine therapy and cannot replace medical supervision. The best approach is regular blood tests and dose adjustment by a physician.