For decades, drug after drug has failed to slow the progression of Alzheimer's disease in human trials. How compounds reducing fibril formation in vitro and toxicity in transgenic mice and flies bind to the Aβ toxic oligomers, is unknown. This account reviews recent drugs mainly targeting Aβ, how they were identified and report their successes from in vitro and in vivo experimental studies and their current status in clinical trials. We then focus on recent in vitro and simulation results on how inhibitors interact with Aβ monomers and oligomers, highly desirable knowledge for predicting new efficient drugs. We conclude with a perspective on the future of the inhibition of amyloid formation by small molecules.