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Botanical illustration of Black Walnut
MedicinalSourced entry

Black Walnut

Juglans nigra

A North American tree whose nut hulls contain juglone and other compounds. Black walnut hull is an ingredient in herbal gut formulas, but it hasn't been studied on its own in people.

What is Black Walnut?

Plant family
Juglandaceae, the walnut family
Parts used
The nut hull (pericarp)
Where it grows
Native to North America; introduced into Europe in the early 1600s
Genus
Juglans
Species
nigra

Also called

Black Walnut Hull

Traditionally used for

  • Gut formulas (SIBO
  • parasites)

Traditionally described as

  • Contains juglone

Health topics

Where Black Walnut appears in symptom search, and why. Being listed doesn't mean it's a proven treatment.

Natural compounds

What does the research say?

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

  • Researchers identified 161 plant compounds in black walnut bark, leaves and hulls. Juglone, from the hull, slowed the growth of human cancer cells in lab tests about as well as standard drugs. Juglone is found in all parts of the tree and is known for stopping other plants from growing near it.[1]

Research in people

  • Black walnut hull is an ingredient in several herbal formulas used for SIBO (bacterial overgrowth in the small intestine). In a small chart review of 13 people, these multi-herb formulas cleared SIBO in 60% to 100% of people, but the study was too small to draw conclusions, and black walnut's own effect isn't known.[2]

In short

It hasn't been tested on its own in people; its safety isn't known.

Sources

  1. [1] Comprehensive Characterization of Phytochemical Composition, Membrane Permeability, and Antiproliferative Activity of Juglans nigra Polyphenols — International Journal of Molecular Sciences · DOI: 10.3390/ijms25136930Peer-reviewed study
  2. [2] Biofilm Disruption Enhances Antimicrobial Therapy for Small Intestinal Bacterial Overgrowth and Intestinal Methanogen Overgrowth — Cureus · DOI: 10.7759/cureus.99116Peer-reviewed study

This information is educational and traditional in nature, and is not a substitute for professional medical advice.