Bodybuilding Hormones 101- Thyroid Hormone

    Thyroid hormone

    Thyroid hormone

    Produced by:

    Thyroid stimulating hormone (TSH) is synthesised and secreted by thyrotrope cells in the anterior pituitary gland. Thyroxine (T4) and triiodothyronine (T3) are produced in the thyroid gland.


    TSH is a hormone that regulates the systemic function of the thyroid gland. The thyroid gland is responsible for the production of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Thyroxine and triiodothyronise inhibit the production of TSH by the pituitary via the thyroid feedback loop. This allows the pituitary to decrease TSH production when there is sufficient amounts of circulating thyroid hormone in the blood stream. Thyroid hormone stimulates the metabolism of almost every tissue in the body. T3 and T4 have a vital role in fat loss and the anabolic process. By supporting the anabolic process thyroid hormone increases RNA polymerase I and II, thereby promoting protein synthesis.

    Ensure optimal function by:

    Exercising regularly.

    Ensuring an adequate intake of iodine from your diet.

    A macronutrient balanced diet has an critical role in stimulating or slowing thyroid function.

    Related hormones:

    The hypothalamus manufactures thyrotropin-releasing hormone (TRH). TRH activates the pituitary gland to produce TSH. Insulin and IGF-1 have stimulating effects on the action of TSH. Cortisol inhibits the conversion of T4 into T3.

    Semper Fi

    Semper Fi a former Marine and regular poster on several bodybuilding forums. He contributes regularly on several platforms.