Synephrine is the main "active" compound found in the fruit of a plant called Citrus aurantium. The fruit is also known as zhi shi (in traditional Chinese medicine), and as green orange, sour orange and bitter orange in other parts of the world. Synephrine is chemically very similar to the  and  found in many OTC cold/allergy medications and in a number of weight loss .
 

  Synephrine can be used as a pressor, for shock, for heart failure, for the treatment of bronchial asthma and surgery and anesthesia of basal blood pressure, collapse and shock, body and position hypotension, etc. Alpha - adrenergic receptor agonist, vasoconstrictor, etc.
     1. The effects on cardiovascular acid-insoluble ash and hovenia dulcis decoction, immature bitter orange extract, injection and its active ingredients of frutus aurantii immaturus Flynn hydrochloride intravenous, can significantly enhance the anesthetic dogs of myocardial contractility and pump function index, with a strong heart, shrink blood vessels, improve the total peripheral resistance, and make the left ventricular pressure, and the effect of arterial blood pressure to rise. Modern studies have confirmed that FAI can concentration-dependently increase aorta tension and make aorta smooth muscle contract in rabbits. Synephrine hydrochloride acts as a weight loss promoter by stimulating β-3 adrenergic receptors, resulting in lipid decomposition and subsequent thermogenesis. Most dietary supplements containing synephrine hydrochloride also contain different ingredients, salicylic acid .
     2.The combination of these chemical components can increase the weight loss effect of Synephrine hydrochloride. In this study, the dietary intake and cardiovascular function of rats were evaluated by repeated oral administration of lime water alcohol extract with a standardized content of synephrine hydrochloride. It was found that the lime extract reduced food intake and weight gain, and the ecg of the experimental animals was abnormal.