Here is the entry from Wikipedia

Lisuride is a dopamine and a partial agonist for several serotonin receptors. It is an antagonist at the serotonin 5-HT2B receptor.[1] It has a high affinity for the dopamine D2, D3 and D4 receptors, as well as serotonin 5-HT1A[2] and 5-HT2A/C receptors.[3] While lisuride has a similar receptor binding profile to the more well-known and chemically similar ergoloid N,N-diethyl-lysergamide (LSD) and inhibits dorsal raphe serotonergic neurons in a similar fashion to LSD, a trait which indicates both drugs in the treatment of Parkinson's disease,[4] it lacks the psychedelic effects of its sister compound. Newer findings suggest the lack of psychedelic action arises from the phenomenon of biased agonism. Stimulation of the 5-HT2A protomer within the 5-HT2A-mGlu2 receptor complex evokes psychedelic effects, while these effects do not occur during sole stimulation of monomeric 5-HT2A receptors. Accordingly, different G-proteins are involved.[5][6] Lisurid behaves as an agonist at the 5-HT2AR monomer. Since it competitively antagonises the effects of LSD, it may be regarded as a protomer antagonist of the 5-HT2A-mGluR heteromer.[7] GPCR oligomers are discrete entities and usually possess properties distinct from their parent monomeric receptors.

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