the advantageous preferred method of preparation of the extract is steam distillation hydrolates essential oils aromatic waters but a useful active ingredient can also be obtained by non distillative extraction processes infusion decoction digestion maceration etc the extracts can be formulated using conventional techniques and excipients in the form of sprays creams ointments salves or other forms suitable for topical administration or can be used to prepare medical devices hydrogels sticking plasters transdermal patches armpit pads and foot pads said compositions according to the invention will typically contain 0 5 to 20 by weight of rhus coriaria l extract the dose and administration regimen can be determined by the doctor on the basis of the patient 39 s condition and the severity of the hyperhidrosis broadly speaking as reported in the clinical trials specified below by way of example one application of a spray or cream containing rhus coriaria l extract in the morning preceded by simple washing with soap and water and one application of a cleansing product containing the same extract in the evening may be sufficient according to the results of a study performed on 30 volunteers suffering from serious forms of primary hyperhidrosis it is sufficient to apply said extract to the affected parts localised hyperhidrosis or use it all over the body as a liquid composition generalised hyperhidrosis to obtain better results than conventional medical or.