The primary risk of the ECA stack is in the effect of ephedrine on the heart. Psychological addiction to ephedrine and caffeine are also possible. While Aspirin is not physically addictive, caffeine is, and users develop a tolerance to lowered adenosine levels, leading to withdrawal symptoms from adenosine sensitivity if caffeine use is discontinued too quickly. It is not recommended that the stack be taken past late afternoon as this may contribute to insomnia. Usually, no more than 25 mg of ephedrine, 200 mg of caffeine and 325 mg of Aspirin is consumed in a single dose. These ratios vary across studies and across users but despite variance they all seem to be effective. Typically the ECA stack is consumed two or three times per day in a 1:10:10 or 1:10:15 ratio of ephedrine:caffeine:Aspirin. The effects of caffeine on dopamine levels are usually short lived, but ephedrine's partial action as a dopamine reuptake inhibitor lengthens the duration. Caffeine blocks adenosine receptors which lessens feelings of tiredness, and also increases dopamine levels, resulting in greater concentration, focus, and memory. It directly acts in the brain to increase the release of norepinephrine into the synaptic cleft, and also partially serves as a norepinephrine reuptake inhibitor, thereby also partially functioning as a dopamine reuptake inhibitor due to the shared action between the two terminals. Mechanisms of effect in energy gainĮphedrine acts to increase energy by its actions as a sympathomimetic amine. The final component in weight loss of the ECA stack is that of a simple stimulant the higher epinephrine and norepinephrine levels result in increased aerobic exercise performance and less fatigue. It is estimated that 60% – 75% of the weight loss from using the ECA stack comes from the anorectic effect, and the remainder from thermogenesis. However, these effects only last for about two weeks if the stack is not cycled, as the body becomes tolerant to ephedrine to some degree. It also binds with and competitively inhibits adenosine receptors in the brain, triggering the release of epinephrine and increasing cAMP levels further.Īspirin inhibits prostaglandin production outside of the cells, which, in conjunction with caffeine, greatly prolongs the thermogenic effects and increased metabolism by substaining elevated cAMP levels.Įphedrine also has an anorectic, or appetite-suppressing, effect. This is done via the production of phosphodiesterase inside the cells, and prostaglandins outside the cell, which both lower cAMP levels within the cell.Ĭaffeine inhibits the production of phosphodiesterase inside the cell and therefore slows cAMP breakdown. However, the body's negative feedback system then activates to normalize the metabolism. This causes a thermogenic effect, raising body temperature and increasing the user's metabolism in conjunction with the rest of the stack.

Increased circulating norepinephrine in the body then acts on white adipose tissue by increasing cAMP levels. Ephedrine acts both as a beta agonist and stimulates the release of norepinephrine.

The effects of the ECA stack in weight loss are primarily due to the ephedrine component.

Eca stack without aspirin