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Cascara sagrada (Rhamnus purshiana)


Also listed as: Rhamnus purshiana
Related terms

Related Terms
  • Aloe, aloe-emodin, amerikanische faulbaumrinde, amerikanische faulbaum, anthracene glycosides, anthranoid, anthraquinone, anthroid, anthrone C-glycosides, Artemisia scoparia, ayapin, bearberry bark, bearwood, bitter bark, California buckthorn, carminic acid, casanthranol, cascara buckthorn, cascara fluid extract aromatic, cascara liquid extract, cascararinde, cascara sagrada, cascara sagrada (dried bark), cascara sagrada extract, cascara sagrada fluid extract (bitter cascara), cascarosides, cassia, cassia senna, chittem bark, coffee tree, dihydroxy-anthraquinones, dihydroxy-anthrones, dihydroxy-dianthrones, dogwood bark, emodin, fimbriatone, Frangula purshiana, nepodin, parietin, Persian bark, phytoestrogens, Polygonaceae, purshiana bark, pursh's buckthorn, Rhamnaceae (family), Rhamni purshianae cortex, Rhamnus purshiana, rhein, rheum, sacred bark, sagrada bark, Sagradafaulbaum (German), vegetable laxatives, wahoo plant, xanthoria elegans, yellow bark.

  • Cascara is obtained from the dried bark of Rhamnus purshianus (Rhamnaceae), both a medicinal and poisonous plant. It is found in Europe, western Asia, and in North America from northern Idaho to the Pacific coast in mountainous areas. In Spanish, cascara sagrada means "sacred bark," perhaps because this woody shrub has provided relief for several constipated individuals. Cascara has been used as a tree bark laxative by Native American tribes and Spanish and Mexican priests since the 1800s. The cascara sagrada bark is aged for a year so that the active principles become milder, as freshly dried bark produces too strong a laxative for safe use.
  • Cascara possesses purgative, toxic, therapeutic, and tonic activity. It is most commonly used as an anthraquinone stimulant laxative for bowel cleansing. Stimulant and cathartic laxatives are the most commonly abused laxatives and have the potential for causing long-term damage.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *

Early studies have examined the use of cascara for bowel preparation. Evidence is insufficient to suggest effectiveness over conventional treatments for this indication.


Cascara sagrada is widely accepted as a mild and effective treatment for chronic constipation. However, limited data is available. Additional study is needed before a strong recommendation can be made.

* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

  • Abdominal pain, anal fissures, analgesic (pain reliever), antibacterial, antiparasitic, antiviral (herpes simplex virus II and vaccinia virus), cholagogue (promotes bile flow), dyspepsia (upset stomach), emetic (induces vomiting), flavoring agent, gallstones, hemorrhoids, immunosuppression, leukemia, liver disease, spleen problems, sunscreen, urinary stones.


Adults (18 years and older)

  • There is no proven safe or effective dose for cascara. Traditionally, 20-30 milligrams per day of the active ingredient, hyroxyanthracene derivatives, has been used. This is calculated as cascaroside A, from the cut bark, powder, or extracts. Doses of 300-1,000 milligrams dried bark have also been given at bedtime for constipation. The cascara liquid extract is often given in a dose of 2-5 milliliters three times daily. Traditionally, 4-6 milliliters of aromatic fluid extract have been administered at bedtime for constipation. As a tea, cascara has been given for constipation including a dose of 1 cup of tea, which can be made by steeping 2 grams of finely chopped bark in 150 milliliters of boiling water for 5-10 minutes, and then straining. The appropriate amount of cascara is the smallest dose that is necessary to maintain soft stools.

Children (younger than 18 years)

  • There is no proven safe or effective dose for cascara in children, and use is not recommended. Traditionally, 1-3 milliliters of aromatic fluid extract (typically one half of the adult dose) daily in children two years and older has been used. For the dried bark preparation, 150-500 milligrams daily has been used.


The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.


  • Avoid in individuals with a known allergy or hypersensitivity to cascara or the Rhamnaceae family. Cascara sagrada exposure has resulted in occupational asthma and rhinitis. Symptoms of allergy may include contact urticaria ("hives") or rash.

Side Effects and Warnings

  • Cascara was formerly approved by the U.S. Food and Drug Administration (FDA) as safe and effective, but this designation was removed in 2002 because of a lack of supporting evidence. When taken by mouth, cascara can commonly cause mild abdominal discomfort, colic, and cramps. Long-term use may lead to potassium depletion, albuminuria (albumin in the urine above a specified level indicating potential kidney damage), hematuria (blood in the urine), disturbed heart function, muscle weakness, finger clubbing (enlargement), and cachexia (extreme weight loss). It is purported that the bark of cascara must be aged for one year or heat-treated to remove harsh constituents, which may produce severe vomiting, intestinal cramping, and/or spasms.
  • Cascara sagrada bark is noted in the German Commission E Monographs to be associated with potassium loss. Patients taking cascara sagrada bark for more than one to two weeks may experience hypokalemia. Signs and symptoms include lethargy, muscle cramps, headaches, paresthesias, tetany (painful muscular spasms and tremors), peripheral edema, polyuria (excessive urination), breathlessness, and hypertension (high blood pressure). Use cautiously in children due to the risk of electrolyte loss, specifically low levels of potassium.
  • Mild abdominal discomfort, colic, gastric melanosis (abnormal deposits of melanin), cholestatic hepatitis, ascites (fluid in the abdomen), portal hypertension (high blood pressure), cramps, nausea, vomiting, diarrhea, and cathartic (produces bowel movement) colon have been reported with chronic use of cascara and other anthraquinone laxatives. In some cases, chronic use may also cause pseudomelanosis coli. Pseudomelanosis coli (pigment spots in the lining of the large intestine) is believed to be harmless, usually reverses with discontinuation, and is not directly associated with an increased risk of developing colorectal adenoma or carcinoma.
  • Cascara may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
  • Use cascara cautiously in elderly patients. Weakness, discoordination, and orthostatic hypotension (low blood pressure when standing) may be exacerbated in elderly patients as a result of significant electrolyte loss when stimulant laxatives are used repeatedly to evacuate the colon. Be aware cascara may hasten the passage of all oral medications through the gut, thereby inhibiting their action.
  • Avoid using cascara in people with nausea or vomiting, inflammatory bowel disease, appendicitis, intestinal obstruction, or acute intestinal inflammation. This includes people with Crohn's disease, ulcerative colitis, and appendicitis. It is also contraindicated for people who have ulcers, and abdominal pain of unknown origin. Be aware that prolonged use of cascara may lead to dependence on laxatives for stools and tolerance.

Pregnancy and Breastfeeding

  • Cascara is thought to be excreted into breast milk and may cause diarrhea. Avoid use in pregnant and breastfeeding women.


Interactions with Drugs

  • Cascara may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
  • Cascara may inhibit the absorption of digitalis glycosides, such as digoxin, and decrease their effects on the heart. Consult with a qualified healthcare professional, including a pharmacist, before combining therapies.
  • Cascara has been used as a laxative and laxative-induced diarrhea may result in decreased absorption of isoniazid or sulfisoxazole.
  • Use of cascara with other laxatives may theoretically cause electrolyte and fluid depletion. Theoretically, concomitant use of cascara with diuretics (agents that increase urine flow), corticosteroids (steroids), or potassium depleting drugs may cause excessive loss of potassium.

Interactions with Herbs and Dietary Supplements

  • Cascara may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
  • Theoretically, concomitant use of cascara with diuretic herbs and supplements may cause excessive loss of potassium. Caution is advised in patients taking herbs or supplements that increase the flow of urine, or have diuretic effects.
  • Cascara may inhibit the absorption of digitalis glycosides, such as foxglove, and decrease their cardiac (heart) action. Cascara may also interact with squill. Consult with a qualified healthcare professional, including a pharmacist, before combining therapies.
  • Theoretically, concomitant use of cascara along with potassium depleting herbs, such as horsetail, may increase the risk of potassium depletion. Use of stimulant laxatives or licorice with cascara may also increase the risk of potassium depletion.
  • Cascara induces increased speed of intestinal emptying, which theoretically may result in decreased absorption of vitamin K.

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

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Copyright © 2011 Natural Standard (

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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