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Cascara

Uses

Common names:
Sacred Bark
Botanical names:
Cascara sagrada, Rhamnus purshiani cortex

Parts Used & Where Grown

Cascara is a small to medium-size tree native to the provinces and states of the Pacific coast, including British Columbia, Washington, Oregon, and northern California. The bark of the tree is removed, cut into small pieces, and dried for one year before being used medicinally. Fresh cascara bark has an emetic or vomit-inducing property and therefore is not used.

What Are Star Ratings?

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.

2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

This supplement has been used in connection with the following health conditions:

Used for Why
3 Stars
Constipation
20 to 30 mg of cascarosides per day for no more than ten days
Cascara is considered a stimulant laxative because it stimulates bowel muscle contractions. Cascara has a milder action compared to other stimulant herbs.

Only the dried form of cascara should be used. Capsules providing 20 to 30 mg of cascarosides per day can be used. However, the smallest amount necessary to maintain soft stool should be used.2 As a tincture, 1/4 to 1 teaspoon (1–5 ml) per day is generally taken. It is important to drink eight 6-ounce (180 ml) glasses of water throughout the day while using cascara. Cascara should be taken consecutively for no longer than eight to ten days.3

The laxatives most frequently used world-wide come from plants. Herbal laxatives are either bulk-forming or stimulating.

Stimulant laxatives are high in anthraquinone glycosides, which stimulate bowel muscle contraction. The most frequently used stimulant laxatives are senna leaves, cascara bark, and aloe latex. While senna is the most popular, cascara has a somewhat milder action. Aloe is very potent and should be used with caution. Other stimulant laxatives include buckthorn, alder buckthorn (Rhamnus frangula), and rhubarb (Rheum officinale, R. palmatum).

Traditional Use (May Not Be Supported by Scientific Studies)

Northern California Indians introduced this herb, which they called sacred bark, to 16th century Spanish explorers. As it is much milder in its laxative action than the herb buckthorn, cascara became popular in Europe as a treatment for constipation. Cascara has been an approved treatment for constipation in the U.S. Pharmacopoeia since 1890.1

How It Works

Common names:
Sacred Bark
Botanical names:
Cascara sagrada, Rhamnus purshiani cortex

How It Works

Cascara bark is high in hydroxyanthraquinone glycosides called cascarosides. Resins, tannins, and lipids make up the bulk of the other bark ingredients. Cascarosides have a cathartic action that induces the large intestine to increase its muscular contraction (peristalsis), resulting in bowel movement.4

How to Use It

Only the dried form of cascara should be used. Capsules providing 20–30 mg of cascarosides per day can be used. However, the smallest amount necessary to maintain soft stool should be used.5 As a tincture, 1/4–1 teaspoon (1–5 ml) per day is generally taken. It is important to drink eight 6-ounce (180 ml) glasses of water throughout the day while using cascara. Cascara should be taken consecutively for no longer than eight to ten days.6

Interactions

Common names:
Sacred Bark
Botanical names:
Cascara sagrada, Rhamnus purshiani cortex

Interactions with Supplements, Foods, & Other Compounds

Long-term use of cascara may result in a loss of potassium, which can lead to abnormalities of heart function and may augment the action of digitalis-like medications with fatal consequences.

Interactions with Medicines

Certain medicines interact with this supplement.

What Are Drug Interactions
Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Digoxin

    Loss of potassium due to cascara (Rhamnus purshiani cortex) abuse could theoretically increase the effects of digoxin and other similar heart medications, with potentially fatal consequences. However, no cases of such an interaction have yet been reported.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Explanation Required

  • none

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Common names:
Sacred Bark
Botanical names:
Cascara sagrada, Rhamnus purshiani cortex

Side Effects

Women who are pregnant or breast-feeding, and children under the age of 12 should not use cascara without the advice of a physician. People with an intestinal obstruction, Crohn’s disease, appendicitis or abdominal pain should not employ this herb.7 Long-term use or abuse of cascara may result in weakened bowel function. It may also cause a loss of electrolytes (especially the mineral potassium). Loss of potassium can lead to abnormalities of heart function and may augment the action of digitalis-like medications with fatal consequences.

References

1. Castleman M. The Healing Herbs. Emmaus, PA: Rodale Press, 1991, 99–100.

2. Blumenthal M, Busse WR, Goldberg A, et al. (eds). *The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines.* Boston, MA: Integrative Medicine Communications, 1998, 104–5.

3. Bradley PR, ed. British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 52–4.

4. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 128–30.

5. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 104–5.

6. Bradley PR, ed. British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 52–4.

7. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 104–5.

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