variations of the TSH molecule, which have lower activity, so the pituitary gland would need to produce more TSH to obtain the same overall level of TSH activity. The same TSH concentration may have a different meaning whether it is used for diagnosis of thyroid dysfunction or for monitoring of substitution therapy with levothyroxine. Reasons for this lack of generalisation are Simpson's paradox and the fact that the TSH-T3 shunt is disrupted in treated hypothyroidism, so that the shape of the relation between free T4 and TSH concentration is distorted. Therapeutic A synthetic drug called recombinant human TSH alpha (rhTSHα or simply rhTSH) or thyrotropin alfa (INN) is manufactured by Genzyme Corp under the trade name Thyrogen. It is used to manipulate endocrine function of thyroid-derived cells, as part of the diagnosis and treatment of thyroid cancer. History In 1916, Bennett M. Allen and Philip E. Smith found that the pituitary contained a thyrotropic substance. References External links TSH at Lab Tests Online Anterior pituitary hormones Glycoproteins Hormones of the hypothalamus-pituitary-thyroid axis Human hormones Peptide hormones Pituitary gland Sanofi Thyroid