Black Walnut

Last Editorial Review: 6/11/2021
Other Name(s):

Carya, Carya basilike, Carya persica, Green Black Walnut, Green Walnut, Juglans nigra, Jupiter's Nuts, Nogal Americano, Nogal Negro, Nogueira-preta, Noix, Noix de Jupiter, Noix de Perse, Noix Verte, Noyer d'Amérique, Noyer Noir, Noyer Noir Américain, Nux persica, Nux regia, Schwarze Walnuss, Walnoot, Walnut.

Overview

Black walnut is a tree. People use the outer covering of the nut (the hull) to make medicine.

Black walnut is used to treat parasitic worm infections and certain other infections including diphtheria and syphilis. It is also used for leukemia.

Some people use black walnut as a gargle, apply it to the scalp as hair dye, or put it on the skin to treat wounds.

How does work?

Black walnut contains high concentrations of chemicals called tannins, which can reduce pain and swelling and dry up body fluids such as mucous.

Uses

Insufficient Evidence to Rate Effectiveness for...

More evidence is needed to rate the effectiveness of black walnut for these uses.

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Side Effects

Black walnut is POSSIBLY SAFE for most people when taken by mouth short-term. It is not known what the possible side effects from short-term use might be.

Black walnut is POSSIBLY UNSAFE when applied directly to the skin. It contains a chemical called juglone that might cause tongue or lip cancer, especially if applied daily.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Don't apply black walnut to the skin if you are pregnant or breast-feeding. This topical use is POSSIBLY UNSAFE. There is not enough reliable information about the safety of black walnut taken by mouth if you are pregnant or breast-feeding. Stay on the safe side and avoid use.

**SpecialPrecautions**

Interactions


Medications taken by mouth (Oral drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Black walnut hulls contain a large amount of chemicals called tannins. Tannins absorb substances in the stomach and intestines. Taking black walnut along with medications taken by mouth can decrease how much medicine your body absorbs, and decrease the effectiveness of your medicine. To prevent this interaction, take black walnut at least one hour after medications you take by mouth.

Dosing

The appropriate dose of black walnut depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for black walnut. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

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References

Amarowicz, R., Dykes, G. A., and Pegg, R. B. Antibacterial activity of tannin constituents from Phaseolus vulgaris, Fagoypyrum esculentum, Corylus avellana and Juglans nigra. Fitoterapia 2008;79(3):217-219. View abstract.

Belknap, J. K., Giguere, S., Pettigrew, A., Cochran, A. M., Van Eps, A. W., and Pollitt, C. C. Lamellar pro-inflammatory cytokine expression patterns in laminitis at the developmental stage and at the onset of lameness: innate vs. adaptive immune response. Equine Vet.J 2007;39(1):42-47. View abstract.

Bhargava, U. C. and Westfall, B. A. Antitumor activity of Juglans niga (black walnut) extractives. J Pharm.Sci. 1968;57(10):1674-1677. View abstract.

Black, S. J., Lunn, D. P., Yin, C., Hwang, M., Lenz, S. D., and Belknap, J. K. Leukocyte emigration in the early stages of laminitis. Vet.Immunol.Immunopathol. 1-15-2006;109(1-2):161-166. View abstract.

Blikslager, A. T., Yin, C., Cochran, A. M., Wooten, J. G., Pettigrew, A., and Belknap, J. K. Cyclooxygenase expression in the early stages of equine laminitis: a cytologic study. J Vet.Intern.Med. 2006;20(5):1191-1196. View abstract.

Choi, H. R., Choi, J. S., Han, Y. N., Bae, S. J., and Chung, H. Y. Peroxynitrite scavenging activity of herb extracts. Phytother.Res. 2002;16(4):364-367. View abstract.

Cline, S., Felsot, A., and Wei, L. Determination of methyl 2-benzimidazolylcarbamate in black walnut fruit. J Agric.Food Chem. 1981;29(5):1087-1088. View abstract.

Eaton, S. A., Allen, D., Eades, S. C., and Schneider, D. A. Digital Starling forces and hemodynamics during early laminitis induced by an aqueous extract of black walnut (Juglans nigra) in horses. Am.J Vet.Res. 1995;56(10):1338-1344. View abstract.

Fontaine, G. L., Belknap, J. K., Allen, D., Moore, J. N., and Kroll, D. L. Expression of interleukin-1beta in the digital laminae of horses in the prodromal stage of experimentally induced laminitis. Am.J Vet.Res. 2001;62(5):714-720. View abstract.

Galey, F. D., Beasley, V. R., Schaeffer, D. J., and Davis, L. E. Antagonism in isolated equine digital vessels of contraction induced by epinephrine in the presence of hydrocortisone and an aqueous extract of black walnut (Juglans nigra). J Vet.Pharmacol.Ther. 1989;12(4):411-420. View abstract.

Galey, F. D., Beasley, V. R., Schaeffer, D., and Davis, L. E. Effect of an aqueous extract of black walnut (Juglans nigra) on isolated equine digital vessels. Am.J Vet.Res. 1990;51(1):83-88. View abstract.

Hurley, D. J., Parks, R. J., Reber, A. J., Donovan, D. C., Okinaga, T., Vandenplas, M. L., Peroni, J. F., and Moore, J. N. Dynamic changes in circulating leukocytes during the induction of equine laminitis with black walnut extract. Vet.Immunol.Immunopathol. 4-15-2006;110(3-4):195-206. View abstract.

Loftus, J. P., Belknap, J. K., and Black, S. J. Matrix metalloproteinase-9 in laminae of black walnut extract treated horses correlates with neutrophil abundance. Vet.Immunol.Immunopathol. 10-15-2006;113(3-4):267-276. View abstract.

McConnico, R. S., Stokes, A. M., Eades, S. C., and Moore, R. M. Investigation of the effect of black walnut extract on in vitro ion transport and structure of equine colonic mucosa. Am.J Vet.Res. 2005;66(3):443-449. View abstract.

Montoya, J., Varela-Ramirez, A., Estrada, A., Martinez, L. E., Garza, K., and Aguilera, R. J. A fluorescence-based rapid screening assay for cytotoxic compounds. Biochem Biophys.Res.Commun. 12-24-2004;325(4):1517-1523. View abstract.

Moodley, R., Kindness, A., and Jonnalagadda, S. B. Elemental composition and chemical characteristics of five edible nuts (almond, Brazil, pecan, macadamia and walnut) consumed in Southern Africa. J Environ.Sci.Health B 2007;42(5):585-591. View abstract.

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Riggs, L. M., Franck, T., Moore, J. N., Krunkosky, T. M., Hurley, D. J., Peroni, J. F., de la, Rebiere G., and Serteyn, D. A. Neutrophil myeloperoxidase measurements in plasma, laminar tissue, and skin of horses given black walnut extract. Am.J Vet.Res. 2007;68(1):81-86. View abstract.

SIEGEL, J. M. Dermatitis due to black walnut juice. AMA.Arch.Derm.Syphilol. 1954;70(4):511-513. View abstract.

von Kiparski, G. R., Lee, L. S., and Gillespie, A. R. Occurrence and fate of the phytotoxin juglone in alley soils under black walnut trees. J Environ.Qual. 2007;36(3):709-717. View abstract.

Waguespack, R. W., Cochran, A., and Belknap, J. K. Expression of the cyclooxygenase isoforms in the prodromal stage of black walnut-induced laminitis in horses. Am.J Vet.Res. 2004;65(12):1724-1729. View abstract.

Woeste, K., Burns, R., Rhodes, O., and Michler, C. Thirty polymorphic nuclear microsatellite loci from black walnut. J Hered. 2002;93(1):58-60. View abstract.

Inbaraj JJ, Chignell CF. Cytotoxic action of juglone and plumbagin: a mechanistic study using HaCaT keratinocytes. Chem Res Toxicol 2004;17:55-62. View abstract.