This invention relates to the inhibition of alpha- synuclein aggregation using peptidyl compounds which are retroenantiomers of the alpha- synuclein sequence, in particular retroenantiomers of sequences in the regions between residues 1 to 60 or residues 61 to 96. Peptidyl compounds of the invention may optionally be coupled to doperminergic targeting moieties and/or blood b rain barrier transport moieties and may be useful in the treatment of alpha- synucleinopathies such as Parkinson's disease.
