Neem oil is a vegetable oil pressed from the fruits and seeds of the neem (Azadirachta indica), an evergreen tree. Neem oil is said to have insect repellent and insecticide effects however it has not been proved to be effective against invisible biting mites. In some countries pesticides that contain neem oil are banned. There is some evidence that internal medicinal use of neem oil, may be associated with liver damage in children. There is evidence that neem is effective as a birth control chemical.