GP Clen is a β2 adrenergic agonist with some similarities to ephedrine, but its effects are more potent and longer-lasting as a stimulant and thermogenic drug. It causes an increase in aerobic capacity, CNS stimulation, and an increase in blood pressure and oxygen transportation. It increases the rate at which fat and protein is used up in the body at the same time as slowing down the storage of glycogen. It is commonly used for smooth muscle relaxant properties. These mean that it is a bronchodilator, and tocolytic.