Its primary known mechanism of action is on the beta-2 adrenergic receptor, also known as ADRB2. [1] Beta-2 adrenergic agonists are primarily used to treat asthma and other pulmonary/respiratory disorders. Other long-acting beta-2 adrenergic agonists include salmeterol, formoterol, and bambuterol. Clenbuterol has been popularized in the public mind recently by media portrayals of off-label use for fat loss, as well as some professional athlete doping scandals involving the drug.