Quetiapine-d8 (hemifumarate) is the deuterium labeled Quetiapine hemifumarate. Quetiapine hemifumarate is a 5-HT receptors agonist with a pEC50 of 4.77 for human 5-HT1A receptor. Quetiapine hemifumarate is a dopamine receptor antagonist with a pIC50 of 6.33 for human D2 receptor. Quetiapine hemifumarate has moderate to high affinity for the human D2, HT1A, 5-HT2A, 5-HT2C receptor with pKis of 7.25, 5.74, 7.54, 5.55. Antidepressant and anxiolytic effects[1].