Plant MedicineCascara Sagrada
Cascara Sagrada

Cascara Sagrada

Frangula purshiana

Family: Rhamnaceae

Also known as: Sacred bark, Rhamnus purshiana

At a glance

Best for: Constipation relief
Parts used: Bark (aged)
Common forms: Capsules, Tea, Extract
Evidence level: Well-supported
Cautions: Pregnancy—Avoid; Breastfeeding—Avoid; Not for long-term use; Can cause cramping; Electrolyte loss with chronic use
Digestive
Capsules
Tea
Extract
Western North America
Pacific Northwest

What it is

Cascara sagrada is a deciduous tree native to the Pacific Northwest. The bark contains anthraquinones that stimulate bowel movements.

Traditional use

Native American tribes used the aged bark as a laxative and digestive tonic. Spanish explorers called it 'sacred bark.' Became widely used in conventional medicine.

What modern research suggests (Well-supported)

Well-established as a stimulant laxative. Works by increasing intestinal motility. Effective but carries risks with prolonged use (dependence, electrolyte imbalance).

How people use it

Capsules or tablets (300-1000mg at bedtime), tea (1 tsp aged bark per cup). Effects occur in 6-12 hours. Only for short-term use (1-2 weeks maximum).

Safety + interactions

Not for long-term use—can cause laxative dependence, electrolyte loss, and intestinal damage. Avoid during pregnancy/breastfeeding. May interact with heart medications, diuretics. Cramping is common—reduce dose if severe.

May interact with: Diuretics, Heart medications, Corticosteroids

Name clarity note

Scientific name changed from Rhamnus purshiana to Frangula purshiana; older sources may use the former.

Quality notes

Bark must be aged at least one year before use—fresh bark causes severe cramping. Look for products specifying aged bark.

FAQs

Why must the bark be aged?

Fresh bark contains compounds that cause severe cramping and vomiting. Aging (1+ year) oxidizes these compounds to safer forms.

Can I use it regularly?

No—only for short-term relief. Long-term use can cause dependence and damage the colon.

Community Insights

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Disclaimer: This content is educational and not medical advice. Always consult a qualified healthcare provider before using any herbs or supplements, especially if you are pregnant, nursing, taking medications, or have a medical condition.

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