* Total TBG can be increased (thereby decreasing the THBR) congenitally, or in conditions such as pregnancy (period of increased estrogen) and with the treatment of certain infections such as Hepatitis C. In the latter, reduction of inflammation of the liver results in increased protein synthesis
* Total TBG can be decreased (thereby increasing the THBR) congenitally, or in conditions such as liver failure, protein-losing conditions, or nephrotic conditions. Increased androgen levels will also decrease TBG synthesis, increasing THBR.
* THBR can be directly altered by drugs such as;
** Anticonvulsants such as phenytoin and carbamazepine
** Antinflammatory drugs such as salicylates (Aspirin) or phenylbutazone (NSAID)
** High levels of free fatty acids, commonly seen in acutely ill patients.