In the forthcoming years, the study of the fundamental interactions between gravitational waves (GWs) and matter will be crucial in order to understand what the new generations of GWs detectors
will tell us. We present the inverse bremsstrahlung absorption of GWs as a novel approach to GWs physics that can help set constraints on different physical models. We study the absorption
of GWs in scattering processes of interacting dark matter. The observation of GWs of a given frequency sets constraints on its absorption efficiency. In the case of interacting dark matter, this can translate to constraints on its mass-coupling space, or in its temperature. For this, we parametrize the absorption of GWs in DM halos and in IGM, at low and very high redshifts. We find the arising constraints to be less stringent than existing ones