Thyronorm is Levothyroxine, used to treat thyroid hormone deficiency. Your doctor has titrated, your dose from 50mcg to 125 mcg, because lower doses were not sufficient to maintain your euthyroid state. Though the side effects are mentioned often in the package insert, I am enumerating them. Palpitations, abdominal pain, nausea, anxiety, confusion, agitation, insomnia, weight loss and increased appetite. Symptoms mimic hyperthyroidism. Long-term suppression of TSH values to subnormal levels may cause cardiac side-effects and contribute to decreases in bone mineral density (low TSH levels are also well known to contribute to osteoporosis). 6 monthly check up of Thyroid profile may be needed.