Cascara Sagrada

What is cascara sagrada?

Cascara sagrada, Spanish for “sacred bark,” is the dried, aged bark of Rhamnus purshiana (also classified as Frangula purshiana), a buckthorn tree native to the Pacific Northwest of North America. Native American peoples used it as a laxative for centuries, and it entered Western medicine in the 19th century. Today it shows up in herbal laxatives, “detox” and “colon cleanse” products, and some digestive powders, often alongside senna or aloe.

Commercial products use bark that has been dried and aged. Its active compounds are anthraquinone glycosides called cascarosides.

What the research says

How it works

According to LiverTox, the National Institutes of Health database on drug-induced liver injury, cascara’s anthraquinones act locally as an irritant to the colon, promoting the muscle contractions that move stool along, and they also reduce how much water and electrolytes the colon reabsorbs (LiverTox: Cascara). It is minimally absorbed into the bloodstream. In other words, cascara is a stimulant laxative, in the same family as senna.

Effectiveness

There are few modern controlled trials of cascara on its own. Its laxative action is well established from long clinical use and from the broader anthraquinone class, but evidence for any benefit beyond producing a bowel movement, such as “detox,” weight loss or gut health, is lacking. Weight that seems to drop after using a stimulant laxative is mostly water and stool, not fat.

Safety

LiverTox lists a typical dose of about 300 mg once daily and says cascara is recommended for short-term use only, less than one week. Side effects include abdominal cramps and electrolyte imbalance. Long-term use or misuse can lead to a “cathartic colon” with diarrhea, cramps, weight loss and darkened pigmentation of the colon lining. With longer use of high doses, there have been several published cases of clinically apparent liver injury, which usually resolved after stopping, though rare severe cases have been described. LiverTox also notes that some injuries may have been caused by undisclosed contaminants (LiverTox: Cascara).

For breastfeeding, the NIH LactMed database says maternal cascara intake might cause loose stools in some infants and should be avoided, with other laxatives preferred (LactMed: Cascara Sagrada).

How it’s used in supplements

As a standalone laxative, cascara is sold in capsules or as a liquid extract for occasional constipation. In supplements, it is often blended into “cleanse,” “flat belly” or “regularity” formulas, sometimes inside a proprietary blend that does not state the amount. That matters, because the same ingredient that produces a quick bowel movement is not intended for daily use over months.

If you see cascara on a label, consider these points:

• Use it only for occasional constipation and for no more than about a week unless a clinician advises otherwise.
• Avoid it during pregnancy and breastfeeding, and in children.
• Do not use it with abdominal pain of unknown cause, nausea, vomiting, inflammatory bowel disease or suspected bowel obstruction.
• Talk with a doctor if you take diuretics, corticosteroids, digoxin or other heart rhythm drugs, since potassium loss from laxatives can make these riskier.
• Stop and seek care if you notice yellowing of the skin or eyes, dark urine or unusual fatigue.