This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Sassafras, Sassafras officinale, or S. variifolium, is official in the form of the bark and the oil in the U. S. and a few other countries. The pith was official in the U. S. P. VIII, but in no other standard. The root is official in Japan, and the wood in Austria, Germany, the Netherlands, and Spain.
Sassafras is an aromatic stimulant. The oil is used as a flavoring agent. Mucilage of sassafras pith is a good vehicle and is a demulcent used in acute febrile and inflammatory affections. Externally the oil is a mild rubefacient, and it may be given internally in doses of 3 minims. The dose of safrol is 5 minims.
Synthetic Oil of Sassafras, the Safrol of the U. S. P., is the methylene ether of allyl pyrocatechol, and it serves every purpose for which oil of sassafras is employed externally. It may be given internally in 5-minim doses, though the natural oil in 3-minim doses is preferable.