It is proposed to use peptide fragments and/or derivatives and/or salts of peptide fragments of parathyroid hormone which comply with the structure: R1-NH-AA-R2 where R1 is selected from the group which is formed by -H, the linear saturated or unsaturated acyl group or branched saturated or unsaturated acyl group having from 1 to 24 carbon atoms, which can be functionalised with an -OH, -SH, -COOH or -CONH2 group, or a sterol group which is bonded by a functional group, such as a diacid with the peptide where R2 = -OH, or the OH is functionalised by a linear saturated or unsaturated alkyl group or branched saturated or unsaturated alkyl group having from 1 to 24 carbon atoms or a sterol group where AA corresponds completely or partially to the sequence of amino acids according to SEQ ID No. 1 corresponding to the PTH (28 to 34) region in order to produce a cosmetic preparation and/or pharmaceutical preparation or for treating, in cosmetic terms, the skin and human hair against intrinsic or extrinsic cutaneous deterioration, and for preventing the appearance of deterioration. Furthermore, there are proposed cosmetic preparations which contain a derivative of peptide fragments of parathyroid hormone which comply with the structure R1-NH-AA-R2 where R1 is selected from the group which is formed by -H, by a linear saturated or unsaturated acyl group or branched saturated or unsaturated acyl group having from 1 to 24 carbon atoms, which can be functionalised with an -OH, -SH, -COOH or -CONH2 group, or a sterol group which is bonded by a functional group, such as a diacid with the peptide where R2 = -OH, or the OH group is functionalised by a linear saturated or unsaturated alkyl group or branched saturated or unsaturated alkyl group having from 1 to 24 carbon atoms or a sterol group, where AA corresponds completely or partially to the amino acid sequence according to SEQ ID NO : 1 of the PTH (28-34) region, with the provision that R1 then corresponds to H only when R2 is
