(+)-Rotigotine is the inactive enantiomer of dopamine receptor agonist (-)-Rotigotine. (+)-Rotigotine is weak agonist of dopamine receptor.

GR 103691 is an effective and selective receptor antagonist of the D3DR (dopamine D3 receptor). GR 103691 was shown to have 100-fold higher selectivity for D3DR (dopamine D3 receptor) over the D2DR (dopamine D2 receptor) and D4DR (dopamine D4 receptor) sites. GR 103,691 is functionally active in vivo and will inhibit the hyperactivity response induced by intra-VTA (ventral tegmental area) injection of muscimol in rats.

A-412,997 or A-412997 is a highly selective agonist for the dopamine D4 receptor. In animal tests, it improved cognitive performance to a similar extent as methylphenidate, but without producing place preference or other signs of abuse liability. When dosed systemically, A-412997 crossed the blood brain barrier rapidly. It was suggested, that selective activation of the D4 receptor, A-412997, might represent a target for the treatment of attention deficit hyperactivity disorder without the potential drug abuse liability associated with current psychostimulant therapies.

NGD 94-1 is high affinity D4 receptor ligand, shows selective over D1, D2, D3 and D5 receptors. Displays antagonist activity at the human D4.2 receptor (Ki = 3.6 nM in transfected CHO cells) and exhibits agonist activity at the D4.4 receptor in HEK 293 cells.

WAY-100635 is an achiral phenylpiperazine derivative that originally discovered as an antagotist of 5-HT1A receptor. Later WAY-100635 was described as a potent dopamine D4 receptor agonist. WAY-100635 was in preclinical studies for the treatment of Diabetes mellitus, Anxiety and Cognition disorders, howevere the development was discontinued. Isotope labeled WAY-100635 could be used for the study of central 5-HT 1A receptors with potential for application to the study of neuropsychiatric disorders and to the human pharmacology of psychoactive drugs.