It increases the patient's metabolism. The result is an increased rate of cellular activity (noted by a more rapid utilization of carbohydrates, fats and proteins). It is used by bodybuilders to burn off body excess fat. Most often utilized during contest preparation, one can greatly decrease the amount of stored fat without being forced to severely restrict calories. It is also noted by many that when thyroid hormones are taken in conjunction with steroids, an increased anabolic effect can be seen (noticeably greater than if the steroids are used alone). This is likely due to faster utilization of proteins by the body, increasing the rate for new muscle accumulation.