ephedrine + caffeine + aspirin

The combination of ephedrine, caffeine, and aspirin, commonly referred to as the ECA stack, is a potent thermogenic formulation historically used for weight loss and athletic performance enhancement. Ephedrine acts as a sympathomimetic agent that stimulates the release of norepinephrine and directly activates adrenergic receptors, particularly the beta-3 subtype, to increase metabolic rate and lipolysis. Caffeine acts synergistically by inhibiting adenosine receptors and phosphodiesterase, which prevents the breakdown of cyclic AMP (cAMP) and prolongs the effects of norepinephrine. Aspirin is included to inhibit prostaglandin synthesis; prostaglandins normally provide a negative feedback loop that dampens the thermogenic response, so their inhibition allows for sustained metabolic activation. While effective for short-term weight reduction, the combination is associated with significant cardiovascular risks, including hypertension and arrhythmias, leading to its ban or severe restriction as a dietary supplement by the FDA and other international regulatory bodies.

Brand names

ECA StackECA EliteECA Xtreme

Other names

ECA stackEphedrine, caffeine, and aspirin combination