 Many derivatives have been examined in an attempt to increase the selectivity.Derivatives lacking the arylpiperazine core, such as 4-aryl-1,2,3,6-tetrahydropyridinum chlorine analogues, are more favorable for potency and selectivity over the other two receptors (Figure 7).In 2016 the discovery of novel G protein biased 5-HT2C receptor agonists was published.