Scientific Name/Common Name:Citrus aurantium L. subsp. Aurantium / Bitter orange Part(s) Used: Peel Constituents/Active Ingredients:Many bitter tasting flavonoid glycosides including neohesperidin and naringin; non-bitter flavonoids, such as hesperidin, rutoside, sinensetin, nobiletin, tangeretin; between 1-2% essential oil with limonene as the main component (>90%), perillyl alcohol and geraniol; pectins; and furanocoumarins. There are also many phenols contained in the peel including polymethoxylated flavones and numerous hydroxycinnamates.Synephrine, approximately 1-3 mg/g. Overview:The peel of bitter orange (also known as Seville orange) is a leathery exocarp, or skin, containing numerous oil glands. Orange peel tea was traditionally used as a medicine for stimulating the appetite, as well as for treating gastric-juice deficiency and to aid digestion. It is also used in making marmalade. The German Commission E also lists orange peel for treating poor digestion due to hypo-acidity. Orange peel is often used as a flavour enhancer. Extract of orange peel is often included in popular digestive bitters formulas on the market.Extracts of bitter orange with high amounts of synephrine have been marketed as weight loss supplements and their safety has come under question. This is very different in composition from traditional use of dried bitter orange peel. Traditional Use/Benefits/Body Systems:As an appetite stimulant/digestive aid. As a source of antioxidants to tone and protect blood vessels. Clinical Studies/Scientific Research/References: Phenols in citrus peel byproducts. concentrations of hydroxycinnamates and polymethoxylated flavones in citrus peel molasses. J Agric Food Chem. 2001 Jul; 49(7): 3268-73. Wichtl M (ed). 1994. Aurantii pericarpium – Bitter-orange peel (English translation by Norman Grainger Bisset). In Herbal Drugs and Phyto-pharmaceuticals. CRC Press, Stuttgart, pp. 94-95. Disclaimer:This information in our Herbal Encyclopedia is intended only as a general reference for educational purposes. It is not a replacement for medical advice. This content does not provide dosage information, cautions/contraindications, or possible interactions with prescription drugs. Please consult any relevant product labels for detailed information on use and with a medical practitioner for individual health advice.