Methods of improving the appearance of keratinous substances using at least one DHEA derivative such as the skin, hair, eyelashes and/or nails, in particular for preventing or treating cutaneous signs of ageing and/or a faded complexion and/or disorders of pigmentation of the skin or hair and/or drying of the skin and/or hyperseborrhoea and/or imperfections relating to hyperseborrhoea and/or sensitive skin and/or dandruff and/or hair loss and/or canities.