Thyroid hormone is a metabolic hormone secreted by the thyroid gland that regulates temperature, metabolism and cerebral function. It contributes to energy levels and temperature regulation and body warmth. It increases fat breakdown, resulting in weight loss as well as lower cholesterol. It protects against cardiovascular disease and improves cerebral metabolism. It helps to prevent cognitive impairment. Thyroid hormone is probably the safest and most beneficial cholesterol lowering agent, yet it is infrequently used for this.