Sassafras has a long history of herbal use. It was widely employed by many native North American Indian tribes who used it to treat a wide range of complaints, valuing it especially for its tonic effect upon the body[257]. It is still commonly used in herbalism and as a domestic remedy. The root bark and root pith are alterative, anodyne, antiseptic, aromatic, carminative, diaphoretic, diuretic, stimulant and vasodilator[4, 21, 46, 165]. A tea made from the root bark is particularly renowned as a spring tonic and blood purifier as well as a household cure for a wide range of ailments such as gastrointestinal complaints, colds, kidney ailments, rheumatism and skin eruptions[222, 238, 257]. The mucilaginous pith from the twigs has been used as a poultice or wash for eye ailments and is also taken internally as a tea for chest, liver and kidney complaints[222]. An essential oil from the root bark is used as an antiseptic in dentistry and also as an anodyne[213]. The oil contains safrole, which is said to have carcinogenic activity and has been banned from use in American foods - though it is less likely to cause cancer than alcohol[222]. In large doses the oil is poisonous, causing dilated pupils, vomiting, stupor, collapse and kidney and liver damage[4, 238]. The oil has been applied externally to control lice and treat insect bites, though it can cause skin irritation[238].