ECA

The ECA stack is a commonly used fat burning stack consisting of Ephedrine, Caffeine, and Aspirin.

The main component, Ephedrine, is the main active ingredient for weight loss and the caffeine augments its efficacy. The aspirin is added to prevent blood clotting (which may be a side effect of ephedrine) and to aid in the signal transduction of ephedrine via prostaglandin inhibition.

Some proponents of the ECA stack recommend replacing the Aspirin in the stack with either Fish Oil or White willow bark, as Aspirin is linked to various organ side effects and the previous two compounds share the same anti-clotting mechanisms.

Studies have shown that the combination of Ephedrine and Caffeine is superior for fat loss than taking each individually.^[1][2][3] As ephedrine can increase heart rate and caffeine may increase blood pressure (in a naive user), the combination tends to have an additive rather than synergistic toxicological profile.^[4]

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ECA itself, Ephedrine with Caffeine and Aspirin, has been shown numerous times to be safe and well tolerated although the amount of studies on the subject matter pale in comparison to just EC (Ephedrine and Caffeine).

Actually significant side effects come with either dose abuse (OD-ing on the stuff) or when the ECA is taken vicariously through herbs, like a combination of Ma Huang, Kola Nut, and White Willow Bark (sources of E, C, and A; respectively)

Compounds that can further augment an ECA stacks effectiveness, like Green Tea Catechins or Yohimbine, should be approached cautiously. They can be quite potent, but at the same time can open up one to more side-effects.

Combine it with a good hypocaloric diet and exercise, and perhaps you'll lose 66kg over 13 months like this guy

Kurtis Frank

• Do I need to cycle ephedrine?

The Human Effect Matrix looks at human studies (excluding animal/petri-dish studies) to tell you what effect ECA has in your body, and how strong these effects are.

Level of Evidence	Effect	Change	Magnitude of Effect Size	Scientific Consensus	Comments
C	Pain		Minor	100% See study	At least in persons with upper respiratory tract infections, a possible analgesic effect of ephedrine with aspirin exists
C	Nasal Congestion		Minor	100% See study	Due to the ephedrine component, ECA may also reduce nasal congestion
C	Metabolic Rate		Notable	100% See 2 studies	The increase in metabolic rate seen with ephedrine is augmented with the inclusion of both aspirin and caffeine, hence its notable efficacy
C	Weight		Notable	100% See study	Due to both the increase in metabolic rate and reduction in appetite reported, there are notable weight reductions with the ECA stack
C	Blood Pressure			100% See study	No significant alterations in long term blood pressure, although acute spikes are possible due to the ephedrine and caffeine components
C	Heart Rate			100% See study	Heart rate at rest is not affected by ECA supplementation and may indirectly be lowered secondary to weight loss. However, an acute increase in heart rate is possible from... show the stimulatory effects of ephedrine
C	Blood glucose			100% See study	No significant alterations in blood glucose noted with ECA supplementation
C	Insulin			100% See study	No significant alterations in fasting insulin reported
C	Total Cholesterol			100% See study	No significant influence on total cholesterol levels

Three doses of:

• Ephedrine in 24mg (72mg total)
• Caffeine in 200mg (600mg total)
• Aspirin in 81mg (Baby Aspirin) once daily

The ECA stack is usually taken in 6-8 week cycles. Dosages should start off small, before reaching 3 doses a day.

References

1. Astrup A, et al. The effect and safety of an ephedrine/caffeine compound compared to ephedrine, caffeine and placebo in obese subjects on an energy restricted diet. A double blind trial. Int J Obes Relat Metab Disord. (1992)
2. Toubro S, et al. Safety and efficacy of long-term treatment with ephedrine, caffeine and an ephedrine/caffeine mixture. Int J Obes Relat Metab Disord. (1993)
3. Astrup A, et al. Thermogenic synergism between ephedrine and caffeine in healthy volunteers: a double-blind, placebo-controlled study. Metabolism. (1991)
4. Haller CA, Jacob P 3rd, Benowitz NL. Enhanced stimulant and metabolic effects of combined ephedrine and caffeine. Clin Pharmacol Ther. (2004)
5. Agonist-Directed Desensitization of the β2-Adrenergic Receptor
6. Kenakin TP. Cellular assays as portals to seven-transmembrane receptor-based drug discovery. Nat Rev Drug Discov. (2009)
7. Fang Y. Label-Free Receptor Assays. Drug Discov Today Technol. (2011)
8. Fang Y, Ferrie AM. Label-free optical biosensor for ligand-directed functional selectivity acting on beta(2) adrenoceptor in living cells. FEBS Lett. (2008)
9. Receptor internalization and ERK1/2 phosphorylation are dependent on the agonist exposure time
10. The desensitization and resensitization patterns of quiescent A431 cells induced by epinephrine is sensitive to stimulation duration and several inhibitors
11. January B, et al. beta2-adrenergic receptor desensitization, internalization, and phosphorylation in response to full and partial agonists. J Biol Chem. (1997)
12. Characterization of β2-Adrenergic Receptor Dephosphorylation: Comparison with the Rate of Resensitization
13. Sears MR. Adverse effects of beta-agonists. J Allergy Clin Immunol. (2002)
14. Nelson HS. Is there a problem with inhaled long-acting beta-adrenergic agonists. J Allergy Clin Immunol. (2006)
15. Astrup A, et al. Enhanced thermogenic responsiveness during chronic ephedrine treatment in man. Am J Clin Nutr. (1985)
16. Schachtel BP, et al. Demonstration of the analgesic efficacy and dose-response of acetylsalicylic acid with pseudoephedrine. J Clin Pharmacol. (2010)
17. Loose I, Winkel M. Clinical, double-blind, placebo-controlled study investigating the combination of acetylsalicylic acid and pseudoephedrine for the symptomatic treatment of nasal congestion associated with common cold. Arzneimittelforschung. (2004)
18. Horton TJ, Geissler CA. Post-prandial thermogenesis with ephedrine, caffeine and aspirin in lean, pre-disposed obese and obese women. Int J Obes Relat Metab Disord. (1996)
19. Horton TJ, Geissler CA. Aspirin potentiates the effect of ephedrine on the thermogenic response to a meal in obese but not lean women. Int J Obes. (1991)
20. Daly PA, et al. Ephedrine, caffeine and aspirin: safety and efficacy for treatment of human obesity. Int J Obes Relat Metab Disord. (1993)

(Common misspellings for ECA include EAC, EC)

(Common phrases used by users for this page include what consist of an eca stacker, epinephrine caffeine aspirin, ephedrine caffeine aspirin side effects, eca aspirin or not, ec white willow, ec stack fish oil dose)

(Users who contributed to this page include Sol, KurtisFrank)