Advanced spectral editing techniques have focused mainly on GABA and GSH discrimination and detection. HERCULES, unlike all predecessor sequences, delivers a reliable detection method for GABA and GSH, but also for ascorbate, aspartate, 2-hydroxyglutarate, lactate, NAA and NAAG. However, current analysis methods have not been optimized for HERCULES analysis. We investigated simultaneous LCModel fitting of the concatenated sum and difference spectra calculated from HERCULES data. The concatenated (ConCAT) approach enables the use of all available spectral information. Compared to traditional single-spectrum analysis, ConCAT yielded improved results, with lower coefficients of variation obtained for concentration estimates and Cramér-Rao lower bounds.