Peptide dendrimers and agents are described, which can be used for polymerising fibrinogen and as haemostatic agents. The peptide dendrimers comprise a branched core, and a plurality of fibrinogen-binding peptides separately covalently attached to the branched core. The branched core comprises: i) from two to ten multi-functional amino acid residues, wherein each fibrinogen-binding peptide is separately covalently attached to a multi-functional amino acid residue of the branched core; il) a plurality of multi-functional amino acid residues, wherein one or more fibrinogen-binding peptides are separately covalently attached to each of at least two adjacent multi-functional amino acid residues of the branched core; Hi) a plurality of multi-functional amino acid residues, wherein two or more fibrinogen-binding peptides are separately covalently attached to at least one of the multi-functional amino acid residues of the branched core; iv) a plurality of multi-functional amino acid residues, wherein two or more multi-functional amino acid residues are covalently linked through a side chain of an adjacent multi-functional amino acid residue; or y) a single multi-functional amino acid residue, and a fibrinogen-binding peptide is separately covalently attached to each functional group of the multi-functional amino acid residue, The. multi-functional amino acid residues comprise tri- or tetra-functional amino acid residues, or tri- and tetra-functional amino acid residues, or the single multi-functional amino acid residue is a tri- or tetra-functional amino acid residue.La présente invention concerne des dendrimères et des agents peptidiques qui peuvent être utilisés pour la polymérisation de fibrinogènes et en tant qu'agents hémostatiques. Les dendrimères peptidiques comprennent un noyau ramifié et une pluralité de peptides se liant à un fibrinogène séparément liés de façon covalente au noyau ramifié. Le noyau ramifié comprend : i) de deux à dix résidus d'acide aminé multi-f