The present invention relates to the use of tripeptide derivatives for tightening, firming and/or moisturizing skin. Furthermore, the invention relates to a method for stimulating the synthesis of glycosaminoglycans containing a D-glucosamine and/or N-acetyl-D-glucosamine residue and/or proteoglycans by fibroblasts and/or keratinocytes such as in particular the synthesis of Hyaluronic acid and/or of the proteoglycans Decorin and/or Lumican.
