SYNOPSISRecently, three pilot studies have proposed that the addition of products containing aspartame to thediets of migraine headache sufferers may produce a significant increase in the frequency of theirmigraines. The present study was a controlled thirteen‐week, double‐blind, randomized cross‐over studycomparing the effect of aspartame to that of a matched placebo on the frequency and intensity of migraineheadache. The results of this study indicated that the ingestion of aspartame by migraineurs caused asignificant increase in headache frequency for some subjects. The implications of these findings andsuggestions for further research are disc