Compounds and compositions are provided for treatment or amelioration of one or more symptoms of a-synuclein toxicity, a-synuclein mediated diseases or diseases in which a-synuclein fibrils are a symptom or cause of the disease. In one embodiment, the compounds for use in the compositions and methods are heteroaryl acylguanidines, heteroarylhydrazones, dihydropyridones, heteroaryl and aryl styryl ketones, and heteroarylpyrazoles.
