Probing the atomic details of intrinsically disordered proteins is crucial to understanding their biological function and relation to pathogenesis. Although amide-detected NMR experiments are widely employed in protein studies, 3JHNHα couplings between amide (1HN) and alpha (1Hα) protons impose an intrinsic limit on the achievable 1HN linewidth. Here, we present a homonuclear decoupling method that narrows the α-synuclein 1HN linewidths to 3-5 Hz. Tightly distributed 1JCαHα coupling values were employed to generate homogeneous antiphase coherences of 2HαzHNy and 4Hα(2)zHα(3)zHNy for nonglycine and glycine residues, respectively, which were combined with their in-phase HNy counterparts to achieve homonuclear decoupling. By reducing the multiplet structure to a singlet, the width of the 1HN cross-peak was reduced by ∼3-fold in the 2D HSQC and 3D intra-HNCA spectra, and good spectral quality was achieved without the need for postprocessing.