Ephedrine and caffeine (EC) combination has been widely used in human obesity treatment. It is known that this drug increases the metabolic rate in both animals and humans. Ephedrine is an agonist of both α and β-adrenoceptors; moreover, it induces norepinephrine release from sympathetic neurons. Caffeine increases both norepinephrine and dopamine release and stimulates the neuronal activity in several brain regions. We hypothesize that EC treatment might exert a specific effect on lipolysis and thermogenesis by stimulation of beta-3 adrenoreceptors on adipose tissue and by stimulating uncoupling of oxidative phosphorylation, i.e. energy being dissipated as heat rather than being converted to adenosine triphosphate (ATP)