Thyroid hormones [predominantly 3, 5, 3 -I- iodothyronine (T3)] regulate 
cholesterol and lipoprotein metabolism but cardiac effects restrict their use as 
hypolipidemic drugs. New molecules have been developped which target 
specifically the thyroid hormone receptor ss, predominant isoform in liver. The 
first thyroid hormone agonist, called GC1, has selective actions compared to T3. 
In animals, GC1 reduced serum cholesterol and serum triglycerides, probably by 
stimulation important steps in reverse cholesterol transport. Other selective 
thyromimetic, KB- 2115 and KB - 141 have similar effects. Another class of 
thyroid hormone analogs, the thyronamines have emerged recently but the basic 
biology of this new class of endogenous thyroid hormone remains to better 
understood. Therefore, these molecules may be a potentially treatment for 
obesity and reduction cholesterol, triglycerides and lipoprotein (a). To date 
the studies in human are preliminary. Tolerance and efficacy of these drugs are 
still under investigation.