Abstract: A depigmenting cosmetic or dermatologic composition for use in bleaching the skin or treating pigmental spots contains in a vehicle suitable for topical application to the skin a benzofuran derivative having the formula ##STR1## wherein the OH function occupies position 5 or 6,R.sub.1 and R.sub.2, each independently, represent hydrogen or alkyl having 1-4 carbon atoms,n is 0 or 1,when n is 0, the C.sub.2 -C.sub.3 bond is a double bond, andwhen n is 1, the C.sub.2 -C.sub.3 bond is a single bond.

Abstract: The invention relates to the use, as coupler in a dyeing composition, of a hydroxybenzofuran of formula (I): ##STR1## in which R.sub.1 and R.sub.2, which are identical or different, represent a hydrogen atom or a C.sub.1 -C.sub.6 alkyl radical. When they denote an alkyl radical, R.sub.1 and R.sub.2 can occupy any position on the benzofuran ring except the positions 2 and 3 at the same time. The OH group may occupy one of the positions 4, 5, 6 or 7, in combination with one or more para type or ortho type oxidation dye precursors or mixtures thereof, for dyeing keratinous fibers and in particular human hair. The dyeing composition according to the invention makes it possible to confer on the keratinous fibers a color which is fast to light, washes, adverse weather conditions and perspiration.