Juglans Nigra (Black Walnut) – Cosmetic Uses in Skin Conditioning and Cleansing

What Is Juglans Nigra?

Juglans nigra, commonly known as black walnut, is a deciduous tree native to eastern and central North America. Different parts of the plant—including the bark, leaves, green fruit hulls and mature seeds—have different chemical compositions and should be considered as distinct cosmetic raw materials.

Cosmetic Uses of Juglans Nigra

Black walnut seed oil can function as a plant-derived emollient and skin-conditioning ingredient. It can be incorporated into creams, lotions, balms, facial oils and other oil-based formulations.

Extracts from the leaves, bark and green hulls contain tannins, phenolic compounds and other constituents that may contribute to astringent and antioxidant properties. Green walnut hulls have traditionally been used in skin cleansing and colouring preparations.

The traditional topical uses of black walnut should be distinguished from scientifically demonstrated cosmetic benefits. Properties observed in concentrated extracts should not automatically be attributed to black walnut seed oil.

Formulation Considerations

The appropriate formulation approach depends on the specific plant part and extraction method. Seed oil can be incorporated into the oil phase of emulsions or used in anhydrous products, while extracts may require different solvent systems.

Hull and bark extracts can contain strongly coloured constituents that may affect the colour and stability of the finished product. Seed oil may also require protection against oxidation due to its unsaturated fatty acids.

Safety and Regulatory Considerations

The safety profile of black walnut seed oil should not be inferred from toxicological data relating to bark, hull or leaf extracts. Concentrated extracts should be evaluated according to their composition, concentration, purity and intended exposure.

The exact botanical identity, plant part, INCI designation, extraction method and supplier specification should be confirmed during cosmetic product development.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

European Medicines Agency. Juglans regia L., folium – European Union herbal monograph.

National Center for Biotechnology Information. PubChem – Juglone.

National Center for Biotechnology Information. PubMed – Juglans nigra and juglone.

European Commission. CosIng – Cosmetic Ingredients Database.

U.S. Department of Agriculture. Juglans nigra L. – Black Walnut.

Bhatia, K. et al. Research on the phytochemistry and biological activities of Juglans nigra and its constituent juglone.