The invention provides a modified therapeutic agent, said modified agent comprising three or more membrane binding elements with low membrane affinity covalently associated with the agent which elements are capable of interacting independently and with thermodynamic additivity, with components of cellular or artificial membranes exposed to extracellular fluids wherein at least two membrane binding elements are lipophilic elements, which may be aliphatic acyl groups, which may be selected from the list consisting of Myristoyl, Decanoyl or Hexanoyl.