Grapefruit essential oil is obtained from the peel of the fruit of the same name, so-called because the fruits hang in bunches like grapes.
In terms of pharmacology, the oil has similar chemical composition and properties to other citrus essential oils. Limonene, for instance, is responsible for the citrus scent of grapefruit, orange and lemon and is present in grapefruit essential oil in a concentration of up to 95%.
Other constituents found in the oil include linalool, citronellol and myrcene, as well as the antioxidants lycopene and vitamins A and C.