Side Effects of ECA Stack

An ECA stack is a commonly used, fast weight-loss supplement. It combines the use of ephedrine, caffeine and aspirin. It is a stimulant and has been around the weight-loss and performance-enhancing industry for decades. But like all diet pills, an ECA stack comes with adverse side effects.


Ephedrine is related to amphetamine or "speed" and is a type of stimulant. It can be found naturally in certain plants and is often used in many energy drinks and various diet pills as "ephedra." Ephedrine is a central nervous system stimulant that is commonly used to treat breathing problems, asthma, hay fever and nasal congestion. "Pseudoephedrine" is found in many cold medications like Sudafed. There are many side effects associated with ephedrine, including increased blood pressure, anxiety, dizziness, headaches, nausea, loss of appetite and insomnia.


Caffeine is also a powerful stimulant, found in many energy drinks, in coffee, tea, soda, chocolate and various other foods. Caffeine has a slight thermogenic effect and can suppress appetite to some degree, but it doesn't have any substantial weight-loss effects when taken alone. High consumption can have many side effects similar to ephedrine, including nausea, muscle tremors, heart palpitations, anxiety, headaches and insomnia. Caffeine can become addictive and withdrawal symptoms include severe headaches, fatigue, sleeplessness, irritability and anxiety.


Aspirin, unlike ephedrine and caffeine, is not a stimulant, but it has been shown to reduce urinary secretion of ephedrine, leaving it in the bloodstream to work longer and have more lasting effects on the body. Taking ephedrine and caffeine alone shows almost the same effects of taking it with aspirin, and there is still speculation as to the role aspirin has on an ECA stack.

How It Works

Ephedrine and caffeine increase levels of norepinephrine, which controls the body's response to stress and initiates the "fight or flight" response that stimulants are used for. This has many effects on the body, such as increasing your heart rate, increases blood pressure, expanding your airways for more oxygen to get in, and slightly increasing your resting metabolic rate (RMR). Norepinephrine also influences the hypothalamus, which helps control your appetite. According to the Student Nutrition Act Committee at UCLA, these effects on the body can help make weight loss possible.


The FDA has linked a number of deaths to the use of ephedrine and weight loss. You should know that any diet pill has risks associated with using it. The effects of an ECA stack being an appetite suppressant are short-lived and only last about two weeks until your body gets used to having the substances in your system. Those taking an ECA stack should cycle it out after about a month of usage, giving your body the time to get back to normal. The weight loss effects of an ECA stack are usually quick and do not last once you stop supplementing them into your diet. If you are looking for long lasting weight-loss results, an ECA stack is not for you.