Cascara sagrada, which means “sacred bark,” refers to the bark of a
shrubby tree that is native to the American Pacific Northwest. The bark
must be aged for at least a year before use to give enough time for the
anthrone glycosides in the bark to degrade. Otherwise, these compounds
would produce strong purgative effects, including intestinal cramping
and vomiting.
In contrast, the aged bark promotes bulk-forming laxative effects. In
fact, the herb was a key ingredient in many over-the-counter (OTC)
stimulant laxatives until it was banned as an ingredient in OTC products
by the U.S. Food and Drug Administration in 2002. Cascara sagrada is
permitted as a dietary supplement, but this herb should not be used for
more than a week and must be taken with sufficient fluids.
