Aspirin, as we saw in the FAQs, blocks the formation of prostaglandins. These prostaglandins normally would blunt the effect of the catecholamines in the synaptic gap. Finally, caffeine antagonizes the adenosine receptor and, more importantly, the phosphodiesterase enzymes within the cell. Check the FAQ entry on caffeine for more specifics. Different studies reach different conclusions as to whether it enhances thermogenesis or not better than just caffeine and ephedrine together.
Tolerance appears to develop after two to four weeks of use.
Fat loss effects seem to reach a point of diminishing returns after 24 weeks. After that point, the stack seems to simply maintain an elevated metabolic rate. Although you may be able to tolerate it better over time, it is still having powerful and effective consequences on your metabolism. Redistribution for personal, noncommercial use is permissible, so long as the document is distributed in its entirety, including this notice. Any other use requires an express written request and consent from the listowner.