Oxidation of lipid membranes is widely known to play a crucial role in many cellular processes and pathological conditions such as apoptosis, inflammation, infection, or sepsis, through direct damage of the cell membrane. Both enzymatic and non-enzymatic oxidation, the latter occurring via direct exposure to reactive oxygen species, are pathways leading to lipid peroxidation in living cells and tissues. The oxidation products have been proposed to function both as signalling molecules and as danger markers for damaged tissue. Oxidative stress has been also implicated in the antimicrobial activities induced by a range of nanomaterials. Here, we aim to characterize the oxidation process of membrane models containing polyunsaturated chains by neutron reflection and to establish the experimental conditions to induce and quantify their oxidation in situ.