The invention relates to a sanitary insert part (1) having an insert housing (2), which (2) includes in a housing interior thereof a functional element (3) that controls throughflow and that has at least one throughflow orifice (4). The insert part according to the invention is characterized in that at least one throughflow opening (4) is delimited by a peripheral wall, the shape of which can be changed against a restoring force as a result of the pressure of the inflowing water in such a manner that the at least one throughflow orifice (4) has a variable orifice cross section which can be changed, in dependence on the pressure of the inflowing water, between an open position and a minimized position having a reduced orifice cross section by comparison.