A formwork element for a molded wall panel end, comprising: a sole plate having a first lateral edge, a second lateral edge, an outer face, an inner face bearing a caisson, said caisson leaving free, on the inner face of the sole plate, a first lateral zone, defined between the first lateral edge and the caisson, and a second lateral zone, defined between the second lateral edge and the caisson; a form stripping assistance device cooperating with the sole plate. The form stripping assistance device includes at least one first sacrificial section comprising a first portion disposed on the first lateral zone of the inner face of the sole plate.