Abnormal tyrosine metabolism occurs in patients with migraine without aura—a condition that can progress to chronic migraine. A recent multicentre study involving 72 patients with chronic migraine and 37 controls has shown that serum levels of tyramine—a derivative of tyrosine—were significantly higher in patients than in controls. The researchers suggest that aberrant tyrosine metabolism could contribute to development of chronic migraine via abnormal activation of neuronal trace-amine receptors.