The invention relates to a method for producing an extract containing at least 40% (m/m) of polyphenols from Cistus creticus L., said method comprising the following steps: plant parts are extracted from Cistus creticus L. using an extraction agent selected from the group comprising water, alcohols and mixtures thereof; the extraction residues are removed; the extraction agent is at least partially removed; redissolution is carried out in an aqueous solvent and the undissolved constituents are removed; and selective enriching is carried out by means of either a) a two-phase extraction, and b) a membrane filtration.