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.
T3 works at the cellular level by increasing the metabolism of protein, carbohydrates, and fats, as well as increasing heart rate and blood flow. T3 is an excellent fat burner since your metabolism is greatly increased while using it.
This benefits bodybuilders in that they can afford to be on a higher calorie pre-contest diet since they’ll burn excess calories with a higher metabolic rate.
Cytomel is best taken several times a day. Levels of T3 will peak roughly 2 hours after ingestion and will be depleted within 4 hours. To optimize the availability of T3 and maintenance of T3 levels throughout the day, multi-dosing is a recommended course of action.
Multi-dosing avoids having total dependence on your body converting T4 to T3.