The seeds produce a thick dark green tamanu oil for medicinal use or hair grease. The first neoflavone isolated in 1951 from natural sources was calophyllolide from C. inophyllum seeds.
Methyl esters of fatty acids derived from seed oil C. inophyllum meet the most important requirements of biodiesel in the United States (ASTM D 6751) and European Union (EN 14214). The average oil yield is 11.7 kg-oil / tree or 4680 kg-oil / hectare. In the northwest coastal areas of Luzon Island in the Philippines, oil was used for night lamps. This widespread use began to decline as kerosene became available, and later on in electricity. It was also used as fuel to generate electricity to power the radios during World War II.
In South India, the oil of the plant seeds is used specifically for the treatment of skin diseases. It is also applied topically in cases of rheumatism. The oil may have been useful in waterproofing fabric and is used as a varnish. An extract of the fruit was once used to make a brown dye to color cloth. The oil can also be used to make soap.
In most of the islands of the South Sea, tamanu or sultan champa oil is used as an analgesic medicine (the natives use it in friction of sciatica and rhematism) and to heal ulcers and bad wounds A farmer in Nagappattinam district of Tamil Nadu Has successfully used Oil as biodiesel to run its 5 HP pump set.