Hey, there, Tracer. If you’re interested, I’m using a text by Daniel Mowrey to answer your question. He wrote a book called “Fat Management! The Thermogenic Factor.” It’s technical treatise of ECA stacks. The first portion of the book is written for and can actually be understood by the layman. The second portion of the book was written to give supplement manufacturers guidance on how to construct an effective and safe ECA stack.
There are 3 series of prostaglandins (hormone-like substances); PGE-1, PGE-2 and PGE-3. The series of prostaglandins above have a number of functions, but as it relates to thermogenesis (the creation of heat by BAT (Brown Adipose Tissue)), PGE-1 and PGE-2 are the players. By increasing the activity of PGE-1 and inhibiiting the actions of PGE-2, cAMP can be controlled.
Additionally where ephedrine alone can cause hypertension in some individuals (and a rise in BP in all individuals to some degree), research shows the ephedrine plus aspirin fails to create a hypertensive action.
Another reason for wanting to control PGE-2 is that it plays an important role in the negative feedback loops that control and modulate the action of NE (norepinephrine/noradrenalin) on the lipolytic (fat breakdown) events of BAT cells. PGE-2, once again is suppressed by anti-inflammatory substances like aspirin.
I can get into the details if you’re interested, but aspirin does not exert a direct, activating effect on any of the events involved in thermogenesis. Rather it helps eliminate one of the events that inhibit thermogenesis.
Questions, comments? Would you like me to go into more detail? (grin)