– Rizatriptan-d6 is intended for use as an internal standard for the quantification of rizatriptan by GC- or LC-MS. Rizatriptan is an agonist of the serotonin receptor subtypes 5-HT1B and 5-HT1D. It is selective for 5-HT1B and 5-HT1D receptors over 5-HT1A receptors. Rizatriptan induces vasoconstriction in isolated human middle meningeal arteries. In vivo, rizatriptan reduces head grooming, the number of oculotemporal strokes, eye blinking, and one-eye closures in a Cacna1a mutant transgenic mouse model of migraine. Formulations containing rizatriptan have been used in the treatment of migraine.