The present invention relates to a composition containing a quinoa grain extract, said extract being a peptidic and osidic extract or a lipidic extract of quinoa grain, said lipid quinoa extract being itself chosen from a group comprising an oil concentrated into its non saponificable fraction, a non saponificable, or a refined oil. The invention also relates to methods for preparing these different extracts and to dermatological or neutraceutic applications of these extracts.