T4 and T3 are both thyroid hormones.

true

the head

T3 and T4 are both thyroid hormones. T3 contains three iodine atoms while T4 contains four iodine atoms. Other than that, they're exactly the same. Taking this prescription medicine when you don't need it will temporarily give your body a disease called hyperthyroidism. The most common symptoms of hyperthyroidism in men are fatigue, sweating, restlessness, changes in appetite, trouble concentrating and weight loss.

it will raise t4 levels