Walnut leaves have been used in the traditional medicine as antimicrobial, antiparasitic, keratolytic, antidiarrheal, hypoglycemic, tonic and gas-stimulating agents; as well as for the treatment of sinusitis, stomach pain and fever.
In many cultures, the plant is used as a local remedy for skin inflammation and excessive sweating of the hands and feet. It is also a common home remedy for the treatment of chronic eczema. The walnut leaves are used locally to treat the scalp in pruritus and dandruff, sunburn and superficial burns, as well as soothing skin diseases. The nuts of walnut help protect the activity of the heart and prevent the loss of bone tissue. The bark, leaves, and the shell of immature green fruits of this curative plant have been used to treat gastric, liver and lung cancer in China. The walnut is used in the traditional medicine in Mexico to protect against liver damage, and the bark is used to clean the teeth. In Nepal the bark is also used for arthritis, skin diseases, toothache, and to stimulate hair growth.
In Bulgarian folk medicine the walnut leaves are used internally for various skin diseases – acne, pyodermitis, herpetiform dermatitis, lymphatic diathesis, also in eczemas and eyelid inflammation. They are also used for the treatment of scrofula (lymphatism). This effect is explained by the toning action of tannin on the body. The walnut leaves are also used in gastroenteritis, to improve appetite and digestion, to flush the mouth in inflammation of the gums, to wash out gynecological diseases. The green nuts of the walnut can be used in hypo and avitaminosis.
External application – the leaves are used in the form of a decoction for rinses and compresses. The fresh leaves are used in addition to bathing water for young children.