Which medication is pure T4?

Levothyroxine is a synthetic form of the hormone thyroxine (T4) and is considered pure T4. This medication is commonly prescribed to treat hypothyroidism, where the thyroid does not produce enough hormones. It works by replenishing the levels of thyroid hormone in the body, helping to maintain normal metabolic processes.

Desiccated thyroid, on the other hand, is derived from the thyroid glands of animals and contains both T4 and triiodothyronine (T3), which is not pure T4. Cytomel is primarily a synthetic version of T3 and does not provide T4 at all, thus not fitting the criteria for pure T4. Tirosint, while being a liquid formulation of levothyroxine, also contains pure T4, but it is not as widely recognized or utilized exclusively for single T4 therapy compared to Levothyroxine. Therefore, Levothyroxine stands out as the standard medication that is specifically pure T4 in its composition.