Lipophilic oligonucleotide comprising a phosphate glycerol unit containing at least one aliphatic unsaturated carbon bond according to formula I with Oligonucleotide = an unmodified or modified nucleic acid of 2 - 1000 nucleotides in length R = a bond or a linker unit Y = OH, SH or NHR3 X and Z = independently O, S or NR3 R3 = hydrogen or branched or unbranched and/or substituted or unsubstituted alkyl, aryl and/or alkyl aryl residue with 10 to 30 carbon atoms R1, R2 = branched or unbranched and/or substituted or unsubstituted alkyl, aryl and/or alkylaryl residue with 10 to 30 carbon atoms, with the provisio that at least one of the residues R1 or R2 comprises at least one aliphatic carbon-carbon double bond Use of lipophilic oligonucleotide according to Formula I for drug discovery or for transfection of cells.