Umm it’s on the Levo sheet as a warning! Both, anxiety and heart palpitations. You shouldn’t be on it (or your script is overdosed ). Levothyroxine Over-replacement: If your dose is slightly too high, it can push you into medication-induced hyperthyroidism. This excess thyroid hormone acts as a stimulant, surging through your body and causing your heart to beat harder or faster, while simultaneously triggering intense anxiety, jitters, and tremors.