Quenching of the Gamow-Teller strength in in weak processes is a well-established phenomenon. I will briefly review our knowledge of quenching of the isospin-analog spin-M1 resonance. The interest is driven by recent developments of ab initio calculations based on interactions derived from χEFT, which allow a unified description of electromagnetic and weak processes populating isospin-analog states. This provides a unique testing ground for the role of two-body currents for the quenching phenomenon. I will also discuss the (very limited) data on quenching of higher multipoles and their implications for astrophysical scenarios and 0vββ decay and present some ideas for future experimental work using transverse electron scattering.