The present invention provides pharmaceutical compositions comprising substituted 1,4 naphthoquinones that are effective in preventing oligomerization of beta amyloid and subsequent pathologies associated with amyloid fibrils. These compositions are useful for the treatment of disease involving amyloidogenesis including neurodegenerative diseases such as Alzheimers Disease or senile dementia. Particularly effective compositions comprise 1,4 naphthoquinones substituted with an amino acid residue selected from a heterocyclic or aromatic amino acid.