simultaneous editing of gaba and glutathione at 7t using semilaser localization purpose to demonstrate simultaneous editing of the two most commonly edited and overlapping signals aminobutyric acid gaba and glutathione gsh with hadamard encoding and reconstruction of megaedited spectroscopy hermes using slaser localization at 7tmethods density matrix simulations of hermes at 7t were carried out and compared with phantom experiments additional phantom experiments were performed to characterize the echo time te dependent modulation of gaba and gshedited hermes spectra at te of 80160 ms in vivo experiments were performed in 10 healthy volunteers comparing hermes 11min to sequentially acquired megaslaser detection of gaba and gsh 211minresults simulations of hermes show gaba and gshedited spectra with negligible levels of crosstalk and give modest agreement with phantom spectra the te series of gaba and gshedited hermes spectra modulate as a result of t2 relaxation and coupling evolution with gaba showing a stronger tedependence in vivo hermes experiments show welledited gaba and gsh signals measured concentrations are not statistically different between hermes and megaslaser for gaba 1 0510254 iu and 10530248 iu p0985 or gsh 03000091 iu and 03020093 iu p0940conclusion simulated phantom and in vivo measurements of hermes show excellent segregation of gaba and gshedited signals and excellent agreement with separately acquired megaslaser data hermes allows twofold acceleration of editing while maintaining spectral quality compared with sequentially acquired megaslaser measurements magn reson med 80474479 2018 2017 international society for magnetic resonance in medicine