Ephedrine
Ephedrine is a sympathomimetic amine that raises metabolic rate and suppresses appetite. It is the classic basis of the ECA stack (ephedrine, caffeine, aspirin), which has the best human evidence of any over-the-counter-style fat-loss combination. It reliably works but raises blood pressure and heart rate, and its sale is restricted because it is a precursor for methamphetamine synthesis.
01 Overview
Ephedrine acts both directly on adrenergic receptors and indirectly by promoting noradrenaline release. This raises metabolic rate, promotes thermogenesis and lipolysis, and suppresses appetite. Medically it has been used as a bronchodilator and to raise blood pressure. Its stimulant and cardiovascular effects define both its usefulness and its risks.
The ephedrine-caffeine combination (with caffeine potentiating the effect; aspirin historically added to prolong it) is among the best-studied fat-loss interventions, with controlled trials showing modest but real additional weight loss over diet alone. Its drawbacks are raised blood pressure and heart rate, insomnia and jitteriness, and rare cardiovascular events. Because ephedrine is a methamphetamine precursor, its retail sale is legally restricted in many countries.
02 Mechanism
Mixed-acting sympathomimetic: directly stimulates alpha and beta adrenergic receptors and indirectly increases noradrenaline release. This raises thermogenesis, metabolic rate and lipolysis and suppresses appetite, with concurrent cardiovascular stimulation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| ECA per dose | 20–25 mg | Oral | Classic ECA stack: ~20-25 mg ephedrine with ~200 mg caffeine, taken 2-3 times daily. |
| Daily total | 60–75 mg/day | Oral | Typical total daily ephedrine in fat-loss use; higher totals raise cardiovascular risk. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Increased metabolic rateRaises metabolic rate and thermogenesis, potentiated by caffeine. | thermogenic rise | Clinical | |
| Appetite suppressionReduces appetite, contributing to a modest but real additional weight loss in trials. | modest | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Raised blood pressure and heart rateElevated blood pressure and heart rate; rare serious cardiovascular events reported at higher doses or in susceptible people. | Moderate | Very common | Clinical | |
| Insomnia and jitterinessStimulant-related insomnia, restlessness and tremor, worse with caffeine. | Mild | Very common | Clinical | |
| Palpitations and arrhythmiaPalpitations and, rarely, serious arrhythmias, particularly at high doses or with underlying heart disease. | Severe | Rare | Clinical |