Alder Buckthorn Bark
Frangula alnus
A Strong clinical evidenceFrangula bark is a stimulant laxative for short-term relief of occasional constipation. Use for 1 week at most; not under 12 or in pregnancy.
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At a glance
The EMA classes frangula (alder buckthorn) bark as "well-established use" for short-term relief of occasional constipation. Like senna, it is a stimulant laxative: long-term use can lead to a sluggish bowel, laxative dependence and loss of water and electrolytes. It should only be used if a change of diet or bulk-forming fibre products are not enough.
Updated: October 15, 2026
✓ This herb record is backed by official European Medicines Agency (EMA HMPC) herbal monographs.
What is it used for?
A Strong clinical evidence
Strong clinical evidence: Supported by strong human clinical trials and well-established medicinal use monographs.
How do we rate evidence levels? →Effective for short-term relief of occasional constipation. [1]
How is it used?
Tea
Cut bark equivalent to no more than 30 mg hydroxyanthracene derivatives in 150 ml of boiling water as an infusion, taken at bedtime. Use the lowest dose that gives a comfortable soft stool.
Amount: Once daily; 2–3 times a week is usually enough
Duration limit: 1 week
[1]Safety & interactions
Minimum age: 12 years
Duration limit: 7 days
- Do not use for more than 1 week. If you need a laxative every day, the cause of constipation should be investigated.
- Do not use with bowel obstruction, appendicitis, Crohn's disease, ulcerative colitis, abdominal pain of unknown cause or severe dehydration.
- Do not use in children under 12.
- Contraindicated in pregnancy and breastfeeding.
- People with kidney disease may develop electrolyte imbalance.
Drug interactions
| Medicine / substance | Effect | Severity |
|---|---|---|
| Cardiac glycosides (e.g. digoxin), antiarrhythmics, QT-prolonging medicines | Low potassium from long-term use can increase their effects; ask a doctor first. [1] | Major |
| Diuretics, corticosteroids, liquorice root | May increase potassium loss; ask a doctor first. [1] | Moderate |
Side effects
- Abdominal pain, cramps and watery stools (especially with an irritable bowel); reduce the dose
- Allergic reactions such as itching, hives or rash
- Yellow or red-brown urine, which is not clinically significant
- With long-term use: discoloured bowel lining, loss of water and electrolytes
⚕ When to see a doctor
- If high fever, shortness of breath or purulent/bloody phlegm develops
- If symptoms do not improve within 1–2 weeks or worsen
- If severe abdominal pain, jaundice, rash or allergic reaction occurs
Did you know?
For frangula bark tea, the amount is set by active content (at most 30 mg hydroxyanthracenes), not by the weight of bark. [1]
Frequently asked questions
What is frangula bark used for?
The EMA accepts its short-term use for occasional constipation.
How long can it be used?
At most 1 week. Taking it 2–3 times in that week is usually enough.
Can it be used for weight loss?
No. Using laxatives to lose weight risks water and potassium loss.
Sources
Cite This Page
Alder Buckthorn Bark (Frangula alnus). Herbadex — Doğal Şifa Rehberi (2026). https://herbadex.com/en/herb/alder-buckthorn-bark/
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