The bitter orange tree is native to eastern Africa and tropical Asia. Today, it is grown throughout the Mediterranean region and elsewhere, including California and Florida. Bitter orange oil is used in foods, cosmetics, and aromatherapy products. Bitter orange oil from the tree's leaves is called petitgrain, and oil from the flowers is called neroli. Bitter orange has been used in traditional Chinese medicine and by indigenous people of the Amazon rainforest for nausea, indigestion, and constipation. Current folk or traditional uses of bitter orange are for heartburn, loss of appetite, nasal congestion, and weight loss. It is also applied to the skin for fungal infections such as ringworm and athlete's foot.
The dried fruit and peel (and sometimes flowers and leaves) are taken by mouth in extracts, tablets, and capsules. Bitter orange oil can be applied to the skin.