Complex comprising a peptide carrier of SEQ ID NO:1 GALFLGFLGAAGSTMGAWSQPKR.sub.1KRKVR.sub.2 and an appropriate siRNA, wherein R.sub.1 represents any amino acid residue and more preferably K or S, R.sub.2 is null or represents one of the following groups: cysteamide, cysteine, thiol, amide, linear or ramified C.sub.1-C.sub.6 alkyl optionally substituted, primary or secondary amine, osidic derivative, lipid, phospholipid or cholesterol and said siRNA is selected to silence a target mRNA.