Stack Genius ingredient guide
Cascara Sagrada
The dried bark of a North American shrub containing anthraquinone compounds that act as a stimulant laxative.
Overview
Cascara sagrada — Frangula purshiana, sometimes still labeled Rhamnus purshiana — is the bark of a small tree native to the Pacific Northwest, and it was one of the most common stimulant laxatives on U.S. drugstore shelves for most of the 20th century. In 2002, the FDA removed it from the over-the-counter laxative monograph after determining that manufacturers had not provided adequate safety and effectiveness data, but it remained available as a dietary supplement.
The reason it works — and the reason it has real safety concerns — is a family of compounds called hydroxyanthracene glycosides. These pass into the colon largely intact, where bacteria convert them to compounds that stimulate colonic contractions, producing a bowel movement several hours later.
The most important thing to know is that cascara is a stimulant laxative for short-term use only. Chronic use is associated with electrolyte depletion, dependence, and, in rare cases, liver injury, and it has largely been replaced by safer options in modern constipation care.
Key takeaways
- Stimulant laxative appropriate only for occasional, short-term use — typically less than one week.
- Chronic use can cause electrolyte depletion, laxative dependence, and rare hepatotoxicity.
- Not for use during pregnancy, breastfeeding, or in children.
Practical guidance
What to know before adding Cascara Sagrada
Evidence snapshot
Cascara reliably produces bowel movements about 6 to 12 hours after ingestion — that mechanism is well established. The concerns lie in long-term safety: reports of liver injury, especially with long-term use, and electrolyte disturbances (particularly low potassium) with prolonged stimulant laxative dependence. Modern gastroenterology practice generally favors osmotic laxatives (polyethylene glycol) and fiber-based approaches over stimulant herbs for anything other than short-term use.
What to look for on the label
Look for products that name Frangula purshiana or Rhamnus purshiana, identify the plant part (aged bark — fresh bark is emetic and irritating), and state a specific dose. "Colon cleanse" or "detox" products often include cascara alongside senna, aloe latex, and rhubarb — an aggressive stimulant laxative stack that can cause dramatic cramping and electrolyte loss. Aged bark (dried and stored at least one year, or heat-treated) is standard.
What makes a better product
A better product uses aged bark from a named source, states specific hydroxyanthracene content or extract ratio, and is clearly labeled for short-term occasional use. Avoid "cleanse" kits marketed for daily long-term use — that use pattern is the specific one associated with harm.
Watch-outs
Do not use for more than one week without medical guidance. Watch for signs of electrolyte imbalance — muscle weakness, irregular heartbeat, or unusual fatigue — especially when combined with diuretics or in older adults. Report any signs of liver trouble (dark urine, yellow skin, right-upper-quadrant pain). Contraindicated in inflammatory bowel disease, bowel obstruction, undiagnosed abdominal pain, and pregnancy. Not for children.
Dosing & Timing
Typical short-term dosing is 20 to 30 mg of hydroxyanthracene derivatives (as cascaroside A) once daily at bedtime — timing chosen so the bowel movement occurs the following morning. Do not exceed one week of continuous use without medical supervision. Adequate hydration matters. Effects can vary widely based on individual sensitivity, so start at the lower end of dosing recommendations.
Safety and interaction context
Cramping and diarrhea are the most common side effects. Chronic use causes potassium loss, which can worsen the effects of digitalis, corticosteroids, and diuretics, and can cause serious cardiac issues. Rare cases of liver injury exist and warrant caution in anyone with liver disease. Contraindicated in intestinal obstruction, appendicitis, abdominal pain of unknown cause, inflammatory bowel disease, dehydration, and pregnancy. Breastfeeding: anthraquinones pass into breast milk and may affect the infant.
Sources
- NIH LiverTox — CascaraHepatotoxicity documentation.
- MedlinePlus — Cascara SagradaConsumer overview and safety.
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