Synephrine is an adrenergic agonist that has gained popularity as being an alternative to ephedrine. It is found in many species of plants, however the main source today for synephrine is citrus aurantium, also known as “bitter orange”. Once the ephedra ban took place, many supplement retailers switched ingredients to synephrine or methyl-synephrine for their fat loss products. Methyl-synephrine differs from standard synephrine in that it contains a superior chemical structure. Data suggests that this not only inhibits MAO activity, but also increases the compounds affinity for the beta-adrenergic receptors. It is often compared to octopamine and suggested to primarily activate beta-3 receptors.