The Spanish and Portuguese brought bitter oranges to the Americas in the 1500s. In Chinese folk medicine, bitter orange was used as a tonic and carminative to treat dyspepsia. Dried bitter orange was used to treat ptosis of the uterus and anus, to relieve abdominal distention and diarrhea, and for blood in feces. In Europe, bitter orange flowers and oil have been used as a sedative and as a prophylactic for GI complaints, nervous conditions, gout, sore throat, and insomnia.
The plant has been used to treat toxic and anaphylactic shock, heart conditions, cardiac exhaustion, and cancer. In Brazilian folk medicine it was used as an anticonvulsant and to treat anxiety and insomnia. Bitter orange oil is used extensively to flavor many food products, alcoholic and nonalcoholic beverages, frozen dairy desserts, candy, baked goods, gelatins and puddings, meat and meat products, and condiments and relishes. Its purported uses in the United States include prevention of skin, breast, and colon cancer. In Haiti the plant has been used as an antiseptic and purgative and in Turkey it has been used as a narcotic, sedative, and treatment for scurvy. The plant has been used as a remedy for treatment-resistant fungal skin diseases, and the tincture or extract has been used for treating heartburn.