ECA (Ephedrine/Caffeine/Aspirin)

The ECA stack combines ephedrine, caffeine, and sometimes aspirin to enhance thermogenesis (heat production), fat oxidation, and energy expenditure. It has historically been used as a weight-loss and performance aid, particularly in bodybuilding and cutting phases. Ephedrine is a sympathomimetic compound that stimulates the release of norepinephrine, increasing metabolic rate and promoting fat breakdown. It also suppresses appetite and can increase energy levels. However, it has significant cardiovascular effects, including increased heart rate and blood pressure. Caffeine is a central nervous system stimulant that works by blocking adenosine receptors, reducing fatigue and enhancing alertness. It also increases fat oxidation and can amplify the thermogenic effects of ephedrine. Aspirin (acetylsalicylic acid) is sometimes included to inhibit prostaglandins, which may help prolong the thermogenic and stimulant effects of ephedrine and caffeine. However, its benefit in the stack is debated and not universally included. Effects & Use: The combination is thought to produce synergistic fat loss effects, but results vary between individuals and depend on diet and exercise.