A sympathomimetic compound derived from Citrus aurantium (“bitter orange”). Synephrine is chemically related to ephedrine, and used as a substitute in “ephedra-free” fat burners. It’s been claimed that synephrine is as effective as ephedrine, while producing fewer side effects, but the evidence for this is slim. Synephrine appears to be mildly effective for weight loss, but – as Paul notes in his review “there is no evidence to support dramatic results.”
Synephrine is sometimes confused with “Neo-Synephrine” (aka phenylephrine) – an isomer with different pharmacologic properties.
See Paul’s review, “Synephrine, Citrus Aurantium, Advantra Z™: Potent Fat Burner, Or Total Dud?” for more information.