Zip Code 23803 Population. 23803 is located in the state of Virginia in the Richmond metro area. Zip code 23803 is primarily located in Chesterfield County. Portions of 23803 are also located in Dinwiddie County.The official postal service name used for 23803 is PETERSBURG, Virginia.ip Code 23803 Area Codes. 23803 is located in the state of Virginia in the Richmond metro area. Zip code 23803 is primarily located in Chesterfield County. Portions of 23803 are also located in Dinwiddie County.
Cytomel (T3) is rarely prescribed on its own to address thyroid problems; it is usually prescribed with T4. In the past, cytomel was a scheduled treatment for obesity; however, an increase in heart complications and cardiac stress forced withdrawal of T3 for that application.
While most actions of thyroid hormone are most likely due to T3, most T3 in the body comes from the conversion of T4. The conversion of T4 to T3 is normal in hypothyroid patients. T3 has a very short life span in the body, while the life span of T4 is much longer, ensuring a steady supply of T3.