Sell Tiromel and Bitiron. Tiromel is a thyroid hormone. As a substance it contains synthetically manufactured liothyronine sodium which Tiromel resembles the natural thyroid hormone tricodide-thyronine. The thyroid of a healthy person usually produces two hormones, the better known L-thyroxine and the aforementioned L-triiodine-thyronine. Since Tiromel is the synthetic equivalent of the latter hormone, it causes the same processes in the body as if the thyroid were to produce more of the hormone. It is interesting to note that L-Tiromel is clearly the stronger and more effective of these two hormones. This makes Tiromel more effective than the commercially available L-T4 compounds such as L-thyroxine or T4.