l-carnitine supplementation on migraine indicators were assessed. In this clinical trial, 133 migrainous patients were randomly assigned into three intervention groups: magnesium oxide (500?mg/day), l-carnitine (500?mg/day), and Mg-span class="a-plus-plus emphasis type-small-caps">l-carnitine (500?mg/day magnesium and 500?mg/day-span class="a-plus-plus emphasis type-small-caps">l-carnitine), and a control group. After 12?weeks of supplementation, the checklist of migraine indicators including migraine attacks/month, migraine days/month, and headache severity was completed, and serum concentrations of magnesium and l-carnitine were measured by atomic absorption spectrophotometry and enzymatic UV test, respectively. The results showed a significant reduction in all migraine indicators in all studied groups (p-lt;-.05). The ANOVA results showed a significant reduction in migraine frequency across various supplemented and control groups (p--.008). By separating the effects of magnesium supplementation from other confounding factors such as routine treatments using the repeated measures and nested model, it was clarified that magnesium supplementation had a significant effect on all migraine indicators. Oral supplementation with magnesium oxide and l-carnitine and concurrent supplementation of Mg-span class="a-plus-plus emphasis type-small-caps">l-carnitine besides routine treatments could be effective in migraine prophylaxis; however, larger trials are needed to confirm these preliminary findings." />