Common Names

  • Cascara Sagrada
  • Sacred Bark

For Patients & Caregivers

Cascara is a strong laxative. It has not been shown to treat or prevent cancer.

Cascara is made out of the bark of the Cascara sagrada plant. It is known to stimulate the large intestine and produce a well-documented laxative effect. Cascara also causes water and electrolytes (such as sodium and potassium) to flow into the large intestine and be expelled from the body with the feces. This facilitates bowel passage but also can lead to dangerously low potassium and sodium levels if cascara is used for prolonged periods of time. Scientists have isolated a compound called aloe-emodin from cascara. In laboratory studies, this compound is able to inhibit the growth of tumor cells by halting cell division, but it is unknown if this effect would take place in the human body. Scientists have also studied whether cascara might be a carcinogen, with inconsistent results.

Cascara is one of the ingredients in the Hoxsey herbal therapy, which is promoted for cancer. There is no evidence that the Hoxsey herbal therapy is effective in treating cancer.

  • To relieve constipation
    Scientific evidence supports this use, but prolonged use is not recommended because it can lead to dangerous blood electrolyte imbalances. The FDA warns that cascara is not safe to use as a laxative.
  • To treat cancer
    Laboratory studies show that a compound found in cascara, aloe-emodin, has anticancer activity, but laboratory results are often not transferable to the human body. Clinical trials have not yet been conducted.
  • Long-term use or overdose of cascara can cause electrolyte imbalances, characterized by very low blood levels of potassium, sodium, and chloride. It may lead to liver injury. The FDA has warned that cascara is not safe to use as a laxative.
  • Cascara may be a carcinogen (cancer-causing substance).
  • Certain compounds in cascara can discolor urine and interfere with urinalysis.
  • You are pregnant or nursing (the safety of cascara is not known).
  • You are taking diuretics (cascara can cause excessive loss of potassium).
  • You are taking digoxin (cascara may have additive cardiac effects because it can cause low blood potassium levels).
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For Healthcare Professionals

Rhamnus purshiana

Cascara sagrada is a species of buckthorn plant native to North America. The bark of the plant has been used to relieve constipation. The major constituents are cascarosides that stimulate the large intestine and produce a laxative effect.

In vitro studies indicate that emodin, one of the constituents of cascara, has hepatoprotective (17), neuroprotective (18), and chemopreventive effects (10) (12) (13). Emodin also enhances the cytotoxic effects of some chemotherapeutic agents (14) (15) (19) (20). Human studies have not been conducted to confirm these effects.

A major cause for concern with cascara is that prolonged use or overdose can cause diarrhea, electrolyte imbalance, and hepatitis (7). According to the United States Food and Drug Administration, cascara has not been shown to be safe or effective as a laxative drug (11).
Despite the FDA ruling, cascara continues to be marketed as a dietary supplement. It is also used as an ingredient in the Hoxsey herbal formula, an ineffective alternative cancer treatment.

Food flavoring agent

  • Cancer treatment
  • Constipation

Cascarosides, the major constituents, stimulate the large intestine and produce a well-documented laxative effect (1) (3). Cascarosides increase intestinal motility and lead to propulsive contractions. This results in an increased water and electrolyte content in the lumen, which further facilitates bowel passage. The other constituent emodin has direct excitatory effect on circular smooth muscle cells in the large intestine (9).
Cascara’s anticancer activities may arise from its emodin and aloe-emodin content. In vitro studies show that aloe-emodin induces p53 and p21 expression resulting in cell cycle arrest in the G1 phase (8). However, more studies are needed to confirm this effect. Studies on the carcinogenic effects of cascara have produced conflicting results (4) (5) (6) (10).

Chronic use may cause electrolyte imbalance, especially hypokalemia.
The FDA ruled that cascara is not safe as a stimulant laxative (11).

Reported: Fresh cascara contains anthrones, which may cause vomiting and intestinal cramps.
Toxicity: Excessive use can cause diarrhea and weakness.
(2) (3)
Rare: Cascara has been associated with cholestatic hepatitis (7).
Case Report: Toxic hepatitis has been been reported with use of cascara (16).

Diuretics: Cascara can cause excessive loss of potassium.
Digoxin: Cascara may potentiate cardiac effects.

Decreased serum potassium.
Anthraquinones in cascara may discolor the urine and interfere with diagnostic tests.

  1. Barnes J, et al. Herbal Medicines. Second Ed. London: Pharmaceutical Press; 2002.

  2. DerMarderosian A, editor. The Review of Natural Products. St. Louis: Facts and Comparisons; 1999.

  3. Gruenwald J, et al. PDR for Herbal medicines, Montvale (NJ): Medical Economics Company; 1998.

  4. DeWitte P, et al. Bicascarosides in fluid extracts of cascara. Planta Med 1991;57:440-3.

  5. Food and Drug Administration. May 9, 2002. Accessed March 9, 2015.

  6. Jacobsen C, Semb S, Kromann-Andersen H. [Toxic hepatitis following consumption of the herbal medicinal product Cascara Sagrada]. Ugeskr Laeger. 2009 Nov 9;171(46):3367-9.

  7. Liu T, Jin H, Sun QR, Xu JH, Hu HT. Neuroprotective effects of emodin in rat cortical neurons against beta-amyloid-induced neurotoxicity. Brain Res. 2010 Aug 6;1347:149-60.

  8. Chen RS, Jhan JY, Su YJ, et al. Emodin enhances gefitinib-induced cytotoxicity via Rad51 downregulation and ERK1/2 inactivation. Exp Cell Res. 2009 Sep 10;315(15):2658-72.

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