The invention relates to 1-(R.sup.1)-2-(R.sup.2)-3-(Y--X--NH-A- or Z-A-)-4,5,6,7-R).sub.0-4-indoles, and their acid addition salts where the compounds are basic, wherein A is C.sub.1-4 alkylene, X is >CH.sub.2, >C.dbd.O or >C.dbd.S, and the other symbols have various defined values, and to pharmaceutical, skin-protective and cosmetic compositions which comprise them.