This herb is actually the unripe fruit of a certain plant, which contains the active ingredient synephrine, a natural thermogenic (fat-burning) agent similar to ephedrine, but having none of the latter’s side effects. Synephrine also provides decongestant effects on the respiratory system such as increasing circulation to the head, shrinking swollen tissues, and dilating respiratory passages to improve breathing. Such evidence helps support the use of this herb in herbal nasal decongestants, as well as its use for allergies, asthma, coughs and symptoms associated with colds. What is this herb?