The use of bitter orange originally descends from traditional Chinese medicine, though the use of bitter orange has been adopted into the European practice of herbal medicine as well. Both modalities utilize extracts and preparations of fruit rind. As a bitter herb, bitter orange stimulates the release of bile from the gallbladder, which in turn supports healthy digestion of foods (especially dietary fats), and regular bowel movements. The volatile oils of bitter orange are thought to be relaxing to the smooth muscle of the GI tract, and orange marmalade (traditionally made with bitter and not sweet orange) can make a good breakfast for those with stagnant digestion. Bitter orange is not typically eaten raw. It is usually cooked or processed and used for its flavor and aroma in medicine, cooking, and aromatherapy. The rind can be cooked, extracted, or expressed, the latter resulting in an essential oil. Energetically, bitter orange is considered cooling. The volatile oils, which can have a calming effect on muscular contraction, have a calming effect on the nervous system as well. Bitter orange essential oil is considered relaxing and is used in aromatherapy to uplift and calm the nervous system. Internally, the essential oil and the specific monoterpene limonene was found to support gastric mucus production, which helps to maintain the health of the GI tract tissues. Another monoterpene from bitter orange, β-myrcene, has also been highlighted as supporting the integrity of the gastric mucosa, and supporting cellular glutathione levels. Bitter orange became the subject of controversy due to concentrated extracts containing especially high amounts of synephrine (~6%) that became associated with safety concerns. Fresh bitter orange fruit contains approximately 0.02% p-synephrine. Bitter orange is typically used in small, synergistic amounts in herbal formulas, and synephrine is even produced in the body in small amounts by conversation from tyramine. It is important to note that a single compound from a plant is not representative of the chemical complexity or actions of the whole plant. Therefore, a single compound’s effects (i.e. synephrine) are not equivalent to the effects and chemical complexity of a full spectrum extract (i.e. bitter orange).