Nomenclature	D 1 receptor	D 2 receptor
HGNC, UniProt	DRD1, P21728	DRD2, P14416
Sub/family‐selective labelled ligands	[125 I]SCH23982 (Antagonist) (pK d 9.5) [433], [3 H]SCH‐23390 (Antagonist) (pK d 9.5) [2221]	[3 H]spiperone (Antagonist) (pK d 10.2) [246, 805, 2219] – Rat
Endogenous agonists	dopamine [1897, 1962]	dopamine [252, 573, 1725]
Agonists	fenoldopam [1962]	rotigotine [448], cabergoline (Partial agonist) [1337], aripiprazole (Partial agonist) [2199], bromocriptine [573, 1337, 1725], MLS1547 (Biased agonist) [572], ropinirole [766], apomorphine (Partial agonist) [252, 573, 1337, 1725, 1844], pramipexole [1332, 1725], benzquinamide [677]
Sub/family‐selective agonists	A68930 [1445], SKF‐38393 (Partial agonist) [1897, 1962]	quinpirole [252, 1332, 1539, 1844, 1846, 2019]
Selective agonists	SKF‐83959 (Biased agonist) [377], SKF‐81297 [47] – Rat	sumanirole [1301]
Antagonists	flupentixol (pK i 7–8.4) [1897, 1962]	blonanserin (pK i 9.9) [1487], pipotiazine (pK i 9.7) [1845], perphenazine (pK i 8.9–9.6) [1055, 1761], risperidone (pK i 9.4) [64], perospirone (pK i 9.2) [1762], trifluoperazine (pK i 8.9–9) [1055, 1763]
Sub/family‐selective antagonists	SCH‐23390 (pK i 7.4–9.5) [1897, 1962], SKF‐83566 (pK i 9.5) [1897], ecopipam (pK i 8.3) [1963]	haloperidol (pK i 7.4–8.8) [573, 1230, 1332, 1844, 1963]
Selective antagonists	–	L‐741,626 (pK i 7.9–8.5) [688, 1069], domperidone (pK i 7.9–8.4) [573, 1844], raclopride (pK i 8) [1339], ML321 (pK i 7) [2147, 2148]
Labelled ligands	–	[3 H]raclopride (Antagonist) (pK d 8.9) [1081] – Rat