Fat Loss: GW1516
Avandia has gotten a lot of press recently for its cardiovascular side effects. PPAR beta/delta is a single receptor but has two designations based on its discovery by two separate teams. I will refer to it as simply Delta. The delta receptor has diverse actions that are distinct from the other two receptor subtypes. GW1516 activates the delta receptor and has been referred to as an “exercise pill”. Activation of the delta receptor switches fuel utilization in skeletal muscle from carbohydrates to fatty acids. This results in more fat being burned and an increase in endurance exercise capacity. It has been shown that exercise induces the upregulation of PPAR delta in skeletal muscle. The increased utilization of fatty acids by skeletal muscle also reduces plasma cholesterol and triglyceride levels.
There are concerns that activation of PPAR delta may progress the growth of tumors both directly and through the stimulation of blood vessel growth called angiogenesis. Angiogenesis can be beneficial in skeletal muscle and the heart to increase blood flow and oxygenation. In tumors, angiogenesis feeds the tumor causing them to grow larger. GW1516 has also been shown to induce growth of the heart, a potentially serious side effect.