Malabsorption of thyroid hormones ... or simply poor patient compliance

: We report the case of a patient presenting with L-thyroxine pseudomalabsorbtion, a figure in which patients are in a state of biological, and, frequently, clinical hypothyroidism secondary to a lack of adherence to substitutive thyroid treatment. We then review the different causes of true thyroid hormones malabsorption and the different approaches to these situations. We also suggest diagnostic and therapeutic attitudes for clinicians facing suspicious cases of hormone malabsorption.