The invention relates to 1-(R?1)-2-(R2¿)-3-(Y-X-NH-A- or Z-A-)-4,5,6,7-(R)¿0-4?-indoles, and their acid addition salts where the compounds are basic, wherein A is C1-4 alkylene, X is > CH2, > C=O or > C=S, and the other symbols have various defined values, and to pharmaceutical, skin-protective and cosmetic compositions which comprise them.