Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Cascara has none that clears that bar.
Stitching two separate single-ingredient studies into a pairing is the one thing this engine will not do. When a study of the combination itself holds up at source, it lands here with its citation.
No invented synergy. Where actives were studied on their own rather than together, the record shows each on its own evidence, never a combined effect no trial measured.
Research strength. Research strength says how much work stands behind the combination. It is never a product score.
Independent record. Every finding is cited to a named trial, dated, and never written by the brand.
20 pairings are live across the library today. Checked 20 July 2026.
No study gave these as a pair, so they are not in the card above. But the reason they belong together is settled biochemistry, not a guess, so it is worth knowing.
The anthraquinone glycosides in cascara bark pass the small intestine intact and are cleaved by bacterial beta-glucosidases in the colon to the active aglycone. Someone whose colonic flora has been depleted, after antibiotics for instance, converts less and responds less. This dependency is the clearest reason the same amount produces different effects in different people.
Psyllium works mechanically by holding water and adding bulk, while cascara's anthrones act on colonic secretion and motor activity. Blends of the two exist, and the usual clinical preference is to start with the bulking agent because stimulant anthraquinones are meant for occasional rather than habitual use. Both need adequate fluid intake to work as intended.
The two mechanisms are separate and their effects on stool water and passage add. Combined at ordinary amounts the result can overshoot into cramping and fluid loss. Anyone stacking them should regard the combined effect as larger than either alone.
Increased colonic secretion and faster transit carry potassium out with the stool, and sustained use of stimulant anthraquinones is a recognised cause of low potassium. This matters most for anyone also taking a diuretic or a cardiac glycoside, where potassium status changes drug effect. It is the single most important handling point for this ingredient class.
Licorice at sustained intake promotes renal potassium loss through 11-beta-hydroxysteroid dehydrogenase inhibition, and stimulant anthraquinones promote faecal potassium loss. The two routes are different and the direction is the same. The pairing appears in some traditional bowel formulas and is worth flagging rather than assuming neutral.
Non-heme iron absorption is slow and depends on contact time with the duodenal mucosa. Anything that accelerates passage lowers the fraction absorbed. Taking an iron dose in the same window as a stimulant laxative works against the iron.
Mucilaginous herbs are put alongside anthraquinone botanicals in traditional formulas on the reasoning that the mucilage softens the effect. This is formulation convention with a long history and no controlled test. The mucilage does not change the bacterial activation step.
Anthraquinone stimulants commonly produce griping, and traditional formulas add aromatic carminatives such as ginger or fennel on the reasoning that they ease it. The practice is old and widespread. Whether it changes anything measurable has not been tested.
Nothing specific on file for Cascara. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.These are the studies our verdict leans on, chosen from the 4 we read for Cascara. The full linked list is below.
2 sources behind our Cascara verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Read this carefully. These are 1,223 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Cascara is, not how risky it is. A report is not proof Cascara caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.