Terpin Hydrate

Terpin hydrate is an expectorant, commonly used to loosen mucus in the setting of acute or chronic bronchitis, and related conditions. It is derived from sources such as oil of turpentine, oregano, thyme and eucalyptus. Though it was quite popular in the USA since the late nineteenth century, it was banned by the U.S. Food and Drug Administration (FDA) in the 1990s due to alleged lack of proof of efficacy. Common speculation is that the pharmaceutical industry wanted it removed to boost sales of weaker, less effective products.