The present invention relates generally to products, compositions and methods useful for promoting neural repair and regeneration. The products and compositions of this invention include myelin-associated glycoprotein (MAG) derivatives that are inhibitors of endogenous MAG (e.g., mutant MAG proteins) and Nogo Receptor (NgR) binding inhibitors that are peptides derived from MAG, Nogo and OMgp that can bind to NgR and block NgR signaling. Peptides that can bind and activate NgR signaling are also provided. Inhibitory MAG derivatives and NgR binding inhibitors are useful for blocking the inhibition of neural regeneration mediated by proteins such as MAG, Nogo and/or OMgp in the nervous system. These inhibitors are also useful for treating neural degeneration associated with injuries, disorders or diseases.