40 years old patient with clinical history that is consistent with Hashimoto’s thyroiditis. After an attempt to replace thyroid function with thyroid hormone in pills (Eutirox), the patient had reported multiple symptoms which might be suggestive for adverse side effects of Eutirox (double vision, tachycardia, disturbance of sleep, outbursts of anger). The patient consulted her family doctor and decided to reduce the dose of Eutirox.