Cascara Sagrada is the common name for the dried bark of the tree Rhamnus purshiana, native to the Pacific Northwest region of North America. The name, meaning “sacred bark” in Spanish, reflects its long history of traditional use as a stimulant laxative. This effect is due to anthraquinone glycosides, primarily cascarosides, found in the bark. These compounds are processed by bacteria in the large intestine to produce active metabolites that stimulate muscle contractions, promoting a bowel movement. Today, its primary use is as a short-term remedy for occasional constipation.
Determining the Appropriate Dosage
Determining a specific dosage is challenging because Cascara Sagrada is sold as a dietary supplement, not a regulated drug, and the FDA has not established a standard safe dose. Traditional use suggests a general effective range for adults seeking relief. A common historical dose of the dried bark extract was around 300 mg, with recommendations ranging up to 600 mg per day.
It is recommended to always begin with the smallest possible dose that produces a soft stool, following the principle of “start low and go slow.” The laxative effect is not immediate, typically requiring six to twelve hours to take effect. Potency relates to the concentration of active compounds (hydroxyanthracene glycosides), making standardized extracts preferred when available.
For fluid extracts, a typical dose is 1 milliliter (ml). Regardless of the form, do not take Cascara Sagrada for more than seven consecutive days. Exceeding this limit or taking higher doses increases the risk of serious side effects. Historical dosing for the dried bark has been cited up to 1 gram (1000 mg), which is generally considered the maximum limit.
Available Forms and Preparation Methods
Cascara Sagrada is available in several forms, including capsules, tablets, syrups, liquid extracts, and the raw dried bark. Commercial capsules and tablets typically contain a standardized amount of extract for ease of dosing. Liquid extracts (fluid extracts or tinctures) are concentrated preparations allowing for precise measurement.
The preparation of the bark is a necessary step that directly impacts safety. Fresh bark contains compounds, primarily anthrones, that are extremely irritating and can cause severe vomiting and intestinal spasms. To mitigate this harsh effect, the bark must be aged for at least one year. This aging process naturally breaks down the irritating anthrones into gentler, active compounds.
Alternatively, the bark can be heat-treated and dried to speed up this process, a method used by commercial manufacturers. When preparing a tea, steep about two grams of finely chopped bark in boiling water for five to ten minutes, then strain the mixture. The dried form is the only preparation permissible for use in herbal remedies.
Essential Safety Guidelines and Warnings
Use must be limited to short-term relief; prolonged use beyond one to two weeks is discouraged due to health risks. Acute side effects include abdominal discomfort, cramping, and diarrhea, common with stimulant laxatives. Extended use risks developing dependency for bowel movements.
Chronic misuse can lead to “cathartic colon,” a functional impairment of the large intestine’s muscles. Prolonged use also causes a significant loss of electrolytes, particularly potassium, which may result in muscle weakness, heart problems, and dehydration. This potassium depletion is especially risky for individuals taking certain heart medications, such as digoxin.
Cascara Sagrada is contraindicated for several populations and conditions. It should not be used by pregnant or breastfeeding women, as the compounds can pass into breast milk and cause diarrhea in a nursing infant. It must also be avoided by anyone with gastrointestinal disorders like appendicitis, intestinal obstruction, Crohn’s disease, ulcerative colitis, or unexplained abdominal pain.
The herb can also interact with other medications, including diuretics, corticosteroids, and blood thinners like warfarin. This interaction potentially increases the risk of bleeding or causes dangerously low potassium levels.