The present invention refers to a method for treating pre-cancerous lesions ofthe skin by administering a pharmaceutically effective amount of a mixture ofpolyphenols to a patient as well as to the production of a medicament thereto,wherein the mixture of polyphenols is a mixture of catechols containing about2-20 % (w/w) epicatechol, about 2-20 % (w/w) epicatechol gallate, about 1-25 %(w/w) epigallocatechol, about 40-75 % (w/w) epigallocatechol gallate, about0.05-5 % (w/w) gallocatechol and/or about 0.5-20 % (w/w) gallocatecholgallate.
