Abstract: The invention relates to a process for preparing high-density quercetin of improved flowability comprising roller compaction of quercetin, wherein both the obtained high-density quercetin and the quercetin starting material have a purity of at least 95%. The invention also relates to the high-density quercetin obtainable with such process, to the use of high-density quercetin for preparing pharmaceutical dosage forms, to pharmaceutical dosage forms comprising high-density quercetin as active ingredient, and to their use in therapy and in cosmetics.