The asymmetry of the natural line profile for transitions in hydrogenlike a
toms is evaluated within a QED framework. For the Lyman-alpha 1s-2p absorpt
ion transition in neutral hydrogen this asymmetry results in an additional
energy shift of 2.929 856 Hz. For the 2s(1/2)-2p(3/2) transition it amounts
to - 1.512 674 Hz. As a new feature this correction turns out to be proces
s dependent. The quoted numbers refer to the Compton-scattering process.