The outer membrane (OM) of gram negative bacteria is mainly constituted of highly polydisperse and amphiphilic lipopolysaccharide (LPS), an endotoxin which is accompanied by lipids and proteins. LPS is a potent inflammatory activator that can, once released from the bacterium, lead to septic shock in humans. It also plays a crucial role in the stability of the OM, acting as a permeability barrier towards external molecules and drugs. Some cationic human antimicrobial peptides (hAMPs) possess the ability of disrupting LPS and other membrane structures. In our study we want to assess how three structurally diverse hAMPs interact with outer membrane models composed of different chemotypes of LPS. We will use neutron reflectivity techniques in order elucidate the mechanism of action of these human peptides in relation to their diverse 3D structure and the employed LPS chemotype models.